CN106813758A - A kind of flow measurement device for borne bacteria sampler - Google Patents
A kind of flow measurement device for borne bacteria sampler Download PDFInfo
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- CN106813758A CN106813758A CN201710095178.2A CN201710095178A CN106813758A CN 106813758 A CN106813758 A CN 106813758A CN 201710095178 A CN201710095178 A CN 201710095178A CN 106813758 A CN106813758 A CN 106813758A
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- 241000894006 Bacteria Species 0.000 title claims abstract description 41
- 238000005259 measurement Methods 0.000 title claims abstract description 35
- 238000010079 rubber tapping Methods 0.000 claims abstract description 79
- 238000012360 testing method Methods 0.000 claims abstract description 30
- 238000006243 chemical reaction Methods 0.000 claims abstract description 21
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- 238000012937 correction Methods 0.000 claims description 20
- 238000001514 detection method Methods 0.000 claims description 11
- 238000012545 processing Methods 0.000 claims description 11
- 238000007789 sealing Methods 0.000 claims description 9
- 238000004364 calculation method Methods 0.000 claims description 2
- 238000010030 laminating Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 5
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 230000006641 stabilisation Effects 0.000 description 5
- 238000011105 stabilization Methods 0.000 description 5
- 230000004888 barrier function Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
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- 238000012795 verification Methods 0.000 description 4
- 239000012530 fluid Substances 0.000 description 3
- 239000003814 drug Substances 0.000 description 2
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- 244000005700 microbiome Species 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
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- 238000005070 sampling Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 229920001817 Agar Polymers 0.000 description 1
- 239000008272 agar Substances 0.000 description 1
- 235000013361 beverage Nutrition 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
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- 239000002609 medium Substances 0.000 description 1
- 230000002906 microbiologic effect Effects 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
- G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters
- G01F25/15—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters specially adapted for gas meters
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Abstract
Measurement apparatus the present invention relates to measure physical quantity, more particularly to a kind of flow measurement device for borne bacteria sampler, including deflector testing agency, wherein, deflector includes the baffle with flow-guiding channel, it is arranged on the orifice plate in flow-guiding channel, the first pressure tappings being opened on baffle and the second pressure tappings and the equal drift net of the air installed in flow-guiding channel porch, testing agency includes air pressure difference sensor and flow rate conversion unit, air pressure difference sensor is used to detect the air pressure difference between the first pressure tappings and the second pressure tappings, flow rate conversion unit is used to that the output signal of air pressure difference sensor process obtaining air mass flow.Apparatus of the present invention are not only simple in structure, low cost, and have the advantages that certainty of measurement is high, good stability, are adapted to dispatch from the factory mode of the borne bacteria sampler using the self-correcting, the calibration of third party testing agency and borne bacteria sampler production unit of enterprise.
Description
Technical field
Measurement apparatus the present invention relates to measure physical quantity, it is more particularly to a kind of for borne bacteria sampler traffic alignment
Flow measurement device.
Background technology
Borne bacteria sampler is the instrument of the plankton in measuring air.Instrument is led to air by getter device
Porous sampling head or slit suction are crossed, is struck on culture dish, the microorganism in air is to be " trapped " on agar medium.
Culture medium is cultivated in microbiological incubator again, microbes in air content can be drawn by counting.Instrument can be answered extensively
For pharmaceuticals industry, food industry, beverage running water, medicine inspecting institute, health and epidemic prevention, hospital, public place etc. about industry and portion
Door.
Borne bacteria sampler is widely used as a kind of ripe instrument in enterprise, laboratory.As China is national
Economic sustainable development and economic structure in-depth transition, gradually contract in industries such as HVAC, purification techniques with the gap of foreign countries
It is small, especially quickly grown in terms of cleaning, microorganism monitoring, measurement.Although domestic enterprise can produce borne bacteria sampler,
Standard set-up for detection flows needs from external import, high cost mostly；And because the standard set-up of import uses impeller
The principle of anemobiagraph, can need to return factory and adjust because use environment difference causes certainty of measurement reduction, there is the cycle long, costly
Problem.And the flow measurement device of Current Domestic manufacture is simpler and cruder, precision is low, stability is poor, and qualification rate is extremely low.
The standard for being used for borne bacteria sampler traffic alignment on Vehicles Collected from Market is mainly the DA- produced by MBV companies
100NT flow verification instrument, the instrument internal has a revolving vane anemometer, by measuring air velocity according to its internal cross-sectional area meter
Flow is calculated, while the temperature and atmospheric pressure of measuring environment.The flow under standard conditions is obtained by the amendment of the two parameters.Instrument
Device measurement range is 90L/min~110L/min, and precision ± 1% can only be calibrated to the borne bacteria sampler of 100L/min,
And China is on the market, borne bacteria sampler mainly has 3 kinds of models of 28.3L/min, 50L/min, 100L/min, for other two
Model is planted, inlet flow rate tester is helpless.
Preferably to promote the quality Control in enterprise technology innovation process, enterprise's testing cost is reduced, researched and developed low
The flow measurement device of the borne bacteria sampler of cost has Great significance.
The content of the invention
To overcome the defect of prior art, the present invention to provide a kind of flow measurement device for borne bacteria sampler.
The present invention is as follows using technical scheme：
A kind of flow measurement device for borne bacteria sampler, including deflector and testing agency,
The deflector includes baffle, the equal drift net of air, the first pressure tappings, the second pressure tappings and orifice plate, described to lead
Fluid has flow-guiding channel, and the orifice plate is arranged in the flow-guiding channel, and the equal drift net of air is arranged on the water conservancy diversion and leads to
The porch in road, the outlet of the flow-guiding channel for connecting the acquisition port of borne bacteria sampler, first pressure tappings and the
Two pressure tappings are opened on the baffle and are connected with the flow-guiding channel, and it is equal that first pressure tappings are located at the air
Between drift net and the orifice plate, second pressure tappings are located between the orifice plate and the outlet of the flow-guiding channel, the hole
Plate is used to make to produce pressure difference between the first pressure tappings and the second pressure tappings；
The testing agency includes air pressure difference sensor and flow rate conversion unit, and the air pressure difference sensor is used to examine
The air pressure difference surveyed between first pressure tappings and second pressure tappings, the flow rate conversion unit is used for the air
The output signal of differential pressure pickup process and obtains air mass flow, and a pressure interface of the air pressure difference sensor is set
In first pressure tappings, another pressure interface is arranged at second pressure tappings.
Preferably, the testing agency also includes the physical quantity inspection at least one physical quantity in detection temperature and air pressure
Survey element and the Signal Processing Element processed for the output signal to the physical quantity detection element.
Preferably, the testing agency is also included for the place to the air mass flow and/or the Signal Processing Element
The output element that reason result is exported.
Preferably, the outer wall of the orifice plate is fitted with the inwall of the baffle, the axle center of the orifice plate and the water conservancy diversion
The axis of passage overlaps, and the aperture plate center has a round hole, and the hole wall of the round hole and the orifice plate are towards described
The end face of the equal drift net of air is vertical.
Preferably, the baffle is hollow cylinder, and the hollow parts of cylinder are the flow-guiding channel, if water conservancy diversion
The internal diameter of passage is D, then the vertical range between the orifice plate and the entrance of flow-guiding channel is 2D, the orifice plate and flow-guiding channel
Outlet between vertical range be D.
Preferably, the vertical range between first pressure tappings and the orifice plate be D, second pressure tappings with it is described
Vertical range between orifice plate is D/2.
Preferably, if a diameter of d of the round hole of the aperture plate center, then the scope of d/D is 0.3-0.7.
Preferably, the testing agency also includes memory cell and amending unit, and the amending unit is deposited with described respectively
Storage unit and the flow rate conversion unit are connected, and the memory cell is used to store correction factor, the correction factor and air
The value range of flow is corresponding, and the amending unit is used to determine that the flow rate conversion cell processing is obtained corresponding to air mass flow
Correction factor, and the air mass flow is modified according to the correction factor；
The amending unit is connected with the output element, and the output element is additionally operable to export revised air stream
Amount.
Preferably, sealed step is additionally provided with the outer wall of the baffle, the sealed step is located at second pressure
Between mouth and the outlet of the flow-guiding channel, the lower surface of the sealed step can closely be pasted with the upper surface of the acquisition port
Close.
Preferably, the outer wall of the baffle is provided with sealing ring, and the sealing ring is located at the sealed step and institute
State between the outlet of flow-guiding channel.
The beneficial effects of the invention are as follows：
(1) flow measurement device that the present invention is provided opens up the first pressure tappings and the second pressure tappings on baffle, passes through
The position and structure for rationally setting orifice plate cause that the first pressure tappings and the second pressure tappings produce air pressure difference, so, measurement first
Can be converted after pressure difference between pressure tappings and the second pressure tappings and obtain air mass flow, its is simple and compact for structure, low cost；With
Compared using the flow verification instrument of revolving vane anemometer principle, in the absence of the problem that certainty of measurement is reduced with use time, with steady
Set, the advantage of long lifespan.Apparatus of the present invention are used cooperatively with borne bacteria sampler, are adapted to borne bacteria sampler and are used enterprise
The mode that dispatches from the factory of self-correcting, the calibration of third party testing agency and borne bacteria sampler production unit.
(2) the equal drift net of air is set in the porch of flow-guiding channel, makes the air-flow for entering flow-guiding channel uniform, and by orifice plate
Ratio control between the diameter d and flow-guiding channel diameter D of upper round hole is between 0.3-0.7, it can be ensured that the first pressure
Suitable and stabilization air pressure difference is produced between mouth and the second pressure tappings, beneficial to the accuracy for improving air mass flow detection.
(3) memory cell and amending unit are set, correction factor are stored by memory cell, using amending unit to preliminary
The air mass flow combination correction factor that treatment is obtained is modified, and can reach the flow measurement range of non-constant width, makes output
Air flow value is more accurate.
Brief description of the drawings
In order to illustrate more clearly of technical scheme, below will be to being wanted needed for embodiment or description of the prior art
The accompanying drawing for using is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present invention, right
For those of ordinary skill in the art, on the premise of not paying creative work, it can also be obtained according to these accompanying drawings
Its accompanying drawing.
Fig. 1 is the front schematic view of the flow measurement device for borne bacteria sampler provided in an embodiment of the present invention.
Fig. 2 is the profile of the flow measurement device for borne bacteria sampler provided in an embodiment of the present invention.
In figure, 1- output elements, the pressure tappings of 2- first, the pressure tappings of 3- second, 4- sealed steps, the equal drift net of 5- air, 6-
Orifice plate.
Specific embodiment
The application is described in further detail with reference to the accompanying drawings and examples.It is understood that this place is retouched
The specific embodiment stated is used only for explaining related invention, rather than the restriction to the invention.It also should be noted that, in order to
Be easy to description, be illustrate only in accompanying drawing to about the related part of invention.
It should be noted that in the case where not conflicting, the feature in embodiment and embodiment in the application can phase
Mutually combination.Describe the application in detail below with reference to the accompanying drawings and in conjunction with the embodiments.
Embodiment 1
Fig. 1 is the front schematic view of the flow measurement device for borne bacteria sampler provided in an embodiment of the present invention, Fig. 2
It is the sectional view of the flow measurement device for borne bacteria sampler that inventive embodiments are provided.Referring to Fig. 1 and Fig. 2, flow is surveyed
Amount device include deflector and testing agency, wherein, deflector include baffle, the equal drift net 5 of air, the first pressure tappings 2,
Second pressure tappings 3 and orifice plate 6, baffle have flow-guiding channel, and orifice plate 6 is arranged in flow-guiding channel, and the equal drift net 5 of air is arranged on
The porch of flow-guiding channel, the equal drift net 5 of air can make the air velocity for entering flow-guiding channel uniform, be conducive to flow-guiding channel to enter
The stability of air pressure at mouthful, the outlet of flow-guiding channel is used to connect the acquisition port of borne bacteria sampler, the first pressure tappings 2 and second
Pressure tappings 3 are opened on baffle and are connected with flow-guiding channel, the first pressure tappings 2 be located at the equal drift net 5 of air and orifice plate 6 it
Between, the second pressure tappings 3 are located between orifice plate 6 and the outlet of flow-guiding channel, and orifice plate 6 is used to make the first pressure tappings 2 and the second pressure
Pressure difference is produced between mouth 3；Testing agency includes air pressure difference sensor and flow rate conversion unit, and air pressure difference sensor is used to examine
The air pressure difference surveyed between the first pressure tappings 2 and the second pressure tappings 3, flow rate conversion unit is used for the defeated of air pressure difference sensor
Go out signal and process to obtain air mass flow, a pressure interface of air pressure difference sensor is arranged at the first pressure tappings 2, another
Individual pressure interface is arranged at the second pressure tappings 3.
Used as a kind of preferred embodiment, baffle is hollow cylinder, and the hollow parts of cylinder constitute above-mentioned water conservancy diversion and lead to
Road, the section of flow-guiding channel is circle, the diameter (i.e. the internal diameter of cylinder) of flow-guiding channel is designated as D, and the orifice plate 6 is shaped as
The circle consistent with the flow-guiding channel section, the center of orifice plate 6 has round hole, the diameter of the round hole (i.e. orifice plate 6
Internal diameter) d is designated as, the hole wall of the round hole is vertical with least one end face of orifice plate 6, and orifice plate 6 can be using engaging or expanded joint etc.
Mode is fixed with the inwall of cylinder, the outer wall of orifice plate 6 is fitted with the inwall of hollow cylinder, the axle center of orifice plate 6 with
The axis of flow-guiding channel is overlapped, also, an end face of the equal drift net 5 of air is close on orifice plate 6 to be hung down with the hole wall of round hole
Straight.The orifice plate 6 is located at 2/3 position of baffle, and the vertical range between orifice plate 6 and the entrance of flow-guiding channel is 2D,
Vertical range between orifice plate 6 and the outlet of flow-guiding channel is D, and the vertical range between the pressure tappings 2 of orifice plate 6 and first is D, hole
Vertical range between the pressure tappings 3 of plate 6 and second is D/2.
As a kind of preferred embodiment, the ratio between the diameter d of the round hole at the center of orifice plate 6 and the diameter D of flow-guiding channel
The scope of value d/D is 0.3-0.7.The value of d/D directly affects the stabilization of the air pressure difference of lower regions and pressure difference in flow-guiding channel
Property, if the value of d/D is excessive, orifice plate 6 is larger to the barrier effect of air, and lower regions air pressure difference is big in flow-guiding channel, pressure
Difference stability is poor, and the pressure difference accuracy that such case is measured is low, and then also inaccurate according to the air mass flow that pressure difference is tried to achieve；
If the value of d/D is too small, orifice plate 6 is smaller to the barrier effect of air, though pressure difference stability in lower regions is good in flow-guiding channel
Air pressure difference is small, and the pressure difference for measuring in this case is too small, can also influence the accuracy of air mass flow, in consideration of it, inventor
By repetition test, when the scope for finding d/D is 0.3-0.7, it can be ensured that the lower regions divided by orifice plate 6 in flow-guiding channel
Between produce size suitable and stabilization air pressure difference, beneficial to the accuracy for improving air mass flow detection, also, to air pressure difference
The sensitivity requirement of sensor is not high, can be with reduces cost.
Flow rate conversion unit is used to that the output signal of the air pressure difference sensor process to obtain air mass flow, empty
The computing formula of throughput is as follows：
In formula
qv：The flow of air, unit is m3/h
C：Efflux coefficient；
β：Diameter is than β=d/D；
ε：The coefficient of expansion；
d：Orifice throttle bore dia, unit is m；
D：Orifice plate pipe diameter, unit is m；
Δp：Pressure difference between the pressure tappings of orifice plate first and the second pressure tappings, unit is Pa；
ρ：The fluid density under temperature and pressure when air mass flow is measured, unit is kg/m3.
Used as a kind of preferred embodiment, the testing agency can also include detector unit, air pressure detecting element, signal
Treatment element, output element 1 and battery module, detector unit is used to detect the temperature of baffle local environment, can be with
It is temperature sensor, air pressure detecting element is used to detect the air pressure of baffle local environment, can is air pressure sensing
Device, Signal Processing Element is used to process the output signal of detector unit and air pressure detecting element, then by exporting
Element 1 is exported result, and output element 1 can be display screen, and battery module is used for as each in testing agency
Device is powered.Output element 1 is also connected with flow rate conversion unit, for the air stream that the treatment of output flow scaling unit is obtained
Amount.Preferably, detector unit, air pressure detecting element, Signal Processing Element, output element 1, battery module, air pressure difference
Sensor and flow rate conversion unit are packaged together, and are then fitted on baffle, and the structure of this integrated form makes testing agency
Small volume, assembling are convenient.Certainly, each part of testing agency can also be each independent.
As a kind of preferred embodiment, sealed step 4 is additionally provided with the outer wall of baffle, sealed step 4 is located at the second pressure
Between mouth 3 and the outlet of flow-guiding channel, the lower surface of sealed step 4 can be tight with the upper surface of the acquisition port of borne bacteria sampler
Laminating.When using, by being vertically installed in the acquisition port of borne bacteria sampler for apparatus of the present invention, due under sealed step 4
Surface and the upper surface form fit of the acquisition port of borne bacteria sampler, can make sealed step 4 by device own wt
Lower surface is brought into close contact with the upper surface of acquisition port, after finishing, removes flow measurement device, flow measurement device with
Need not be fixed by fixture between borne bacteria sampler, using very convenient.
The flow measurement device that the present invention is provided opens up the first pressure tappings and the second pressure tappings on baffle, by reasonable
The position and structure for setting orifice plate cause that the first pressure tappings and the second pressure tappings produce air pressure difference, so, measure the first pressure
Can be converted after pressure difference between mouth and the second pressure tappings and obtain air mass flow, its is simple and compact for structure, low cost；With use
The flow verification instrument of revolving vane anemometer principle is compared, in the absence of the problem that certainty of measurement is reduced with use time, with stablizing,
The advantage of long lifespan.Apparatus of the present invention are used cooperatively with borne bacteria sampler, be adapted to borne bacteria sampler using enterprise self-correcting,
The calibration of third party testing agency and the mode that dispatches from the factory of borne bacteria sampler production unit.
Embodiment 2
The present embodiment provide flow measurement device can be used to be used cooperatively with borne bacteria sampler, including deflector and
Testing agency, wherein, deflector includes baffle, the equal drift net 5 of air, the first pressure tappings 2, the second pressure tappings 3 and orifice plate 6,
Baffle has flow-guiding channel, and orifice plate 6 is arranged in flow-guiding channel, and the equal drift net 5 of air is arranged on the porch of flow-guiding channel, empty
The equal drift net 5 of gas can make the air velocity for entering flow-guiding channel uniform, be conducive to the stability of flow-guiding channel porch air pressure, lead
The outlet of circulation road is used to connect the acquisition port of borne bacteria sampler, and the first pressure tappings 2 and the second pressure tappings 3 are opened in water conservancy diversion
Connected on body and with flow-guiding channel, the first pressure tappings 2 are located between the equal drift net 5 of air and orifice plate 6, the second pressure tappings 3 are located at hole
Between plate 6 and the outlet of flow-guiding channel, orifice plate 6 is used to make to produce pressure difference between the first pressure tappings 2 and the second pressure tappings 3；Detection
Mechanism includes air pressure difference sensor and flow rate conversion unit, and air pressure difference sensor is used to detect the first pressure tappings 2 and second
Air pressure difference between pressure tappings 3, flow rate conversion unit is used to process the output signal of air pressure difference sensor
Air mass flow a, pressure interface of air pressure difference sensor is arranged at the first pressure tappings 2, and another pressure interface is arranged at
Two pressure tappings 3.
Used as a kind of preferred embodiment, baffle is hollow cylinder, and the hollow parts of cylinder constitute above-mentioned water conservancy diversion and lead to
Road, the section of flow-guiding channel is circle, the diameter (i.e. the internal diameter of cylinder) of flow-guiding channel is designated as D, and the orifice plate 6 is shaped as
The circle consistent with the flow-guiding channel section, the center of orifice plate 6 has round hole, the diameter of the round hole (i.e. orifice plate 6
Internal diameter) d is designated as, the hole wall of the round hole is vertical with least one end face of orifice plate 6, and orifice plate 6 can be using engaging or expanded joint etc.
Mode is fixed with the inwall of cylinder, the outer wall of orifice plate 6 is fitted with the inwall of hollow cylinder, the axle center of orifice plate 6 with
The axis of flow-guiding channel is overlapped, also, an end face of the equal drift net 5 of air is close on orifice plate 6 to be hung down with the hole wall of round hole
Straight.The orifice plate 6 is located at 2/3 position of baffle, and the vertical range between orifice plate 6 and the entrance of flow-guiding channel is 2D,
Vertical range between orifice plate 6 and the outlet of flow-guiding channel is D, and the vertical range between the pressure tappings 2 of orifice plate 6 and first is D, hole
Vertical range between the pressure tappings 3 of plate 6 and second is D/2.
As a kind of preferred embodiment, the ratio between the diameter d of the round hole at the center of orifice plate 6 and the diameter D of flow-guiding channel
The scope of value d/D is 0.3-0.7.The value of d/D directly affects the stabilization of the air pressure difference of lower regions and pressure difference in flow-guiding channel
Property, if the value of d/D is excessive, orifice plate 6 is larger to the barrier effect of air, and lower regions air pressure difference is big in flow-guiding channel, pressure
Difference stability is poor, and the pressure difference accuracy that such case is measured is low, and then also inaccurate according to the air mass flow that pressure difference is tried to achieve；
If the value of d/D is too small, orifice plate 6 is smaller to the barrier effect of air, though pressure difference stability in lower regions is good in flow-guiding channel
Air pressure difference is small, and the pressure difference for measuring in this case is too small, can influence the accuracy of air mass flow, in consideration of it, inventor is logical
Repetition test is crossed, when the scope for finding d/D is 0.3-0.7, it can be ensured that the lower regions divided by orifice plate 6 in flow-guiding channel it
Between produce size it is suitable and stabilization air pressure difference, beneficial to improve air mass flow detection accuracy, also, to air pressure difference pass
The sensitivity requirement of sensor is not high, can be with reduces cost.
The computing formula that flow rate conversion unit calculates air mass flow is as follows：
In formula
qv：The flow of air, unit is m3/h
C：Efflux coefficient；
β：Diameter is than β=d/D；
ε：The coefficient of expansion；
d：Orifice throttle bore dia, unit is m；
D：Orifice plate pipe diameter, unit is m；
Δp：Pressure difference between the pressure tappings of orifice plate first and the second pressure tappings, unit is Pa；
ρ：The fluid density under temperature and pressure when air mass flow is measured, unit is kg/m3.
The value that flow rate conversion unit is calculated according to formula (2) is calculated value, it is contemplated that theoretical calculation and reality
The difference for existing is measured, to ensure flow measurement precision, the testing agency also includes memory cell and amending unit, and amendment is single
Unit is connected with memory cell and flow rate conversion unit respectively, wherein, memory cell is used to store correction factor, correction factor and sky
The value range of throughput is corresponding, and amending unit is used to determine that flow rate conversion cell processing obtains the amendment corresponding to air mass flow
Coefficient, and air mass flow is modified according to correction factor.Correction factor be according to the sampling condition of borne bacteria sampler, it is right
Than the calculated value q of air mass flow under the same conditionsIt is theoreticalWith actual measured value qActual measurementBetween ratio, such as correction factor is
K=qIt is theoretical/qActual measurement, range of flow value has been carried out into corresponding storage, as shown in table 1, correction factor with correction factor in memory cell
K1 correspondence range of flows 20L/min~100L/min, the corresponding range of flow 100L/min~500L/min of adjusted coefficient K 2, amendment
The corresponding range of flow 500L/min~1000L/min of COEFFICIENT K 3.
Table 1：
| Correction factor | Range of flow (unit L/min) |
| K1 | 20~100 |
| K2 | 100~500 |
| K3 | 500~1000 |
The theoretical value of the air mass flow that amending unit is further calculated flow scaling unit is modified, to be pressed close to
The air mass flow of actual measured value.Amending unit is modified calculating using formula (3)：
q'v=Kqv (3)
In formula：q'vIt is revised air mass flow, qvIt is the theory that air mass flow is calculated according to above-mentioned formula (2)
Value, K is flow modificatory coefficient.
K is according to q in formula (3)vTo determine, if qvFall into this scope of 100L/min~500L/min, K=K2.
The present embodiment sets memory cell and amending unit, correction factor is stored by memory cell, using amending unit
The air mass flow combination correction factor obtained to preliminary treatment is modified, and makes the air flow value of output more accurate.Compare
It is the flow verification instrument of 90L/min~110L/min in existing measurement range, the present apparatus can reach broader flow measurement
Scope, it is applied widely.
Used as a kind of preferred embodiment, the testing agency can also include detector unit, air pressure detecting element, signal
Treatment element, output element 1 and battery module, detector unit is used to detect the temperature of baffle local environment, can be with
It is temperature sensor, air pressure detecting element is used to detect the air pressure of baffle local environment, can is air pressure sensing
Device, Signal Processing Element is used to process the output signal of detector unit and air pressure detecting element, then by exporting
Element 1 is exported result, and output element 1 can be display screen, and battery module is used for as each in testing agency
Device is powered.Output element 1 is also connected with amending unit, for exporting revised air mass flow.Preferably, temperature detection unit
Part, air pressure detecting element, Signal Processing Element, output element 1, battery module, air pressure difference sensor, flow rate conversion unit,
Memory cell and amending unit can be packaged together, and be then fitted on baffle.Certainly, each part of testing agency also may be used
With each independent.
As a kind of preferred embodiment, sealed step 4 and sealing ring are additionally provided with the outer wall of baffle, sealed step 4 is located at
Between second pressure tappings 3 and the outlet of flow-guiding channel, sealing ring is socketed in the outer wall of baffle, and sealing ring is located at described close
Between envelope step 4 and the outlet of flow-guiding channel.When using, by the collection for being vertically installed at borne bacteria sampler of apparatus of the present invention
On mouth, in the presence of device own wt, upper surface and the lower surface of sealed step 4 of sealing ring are brought into close contact, sealing ring
Lower surface be brought into close contact with the upper surface of the acquisition port of borne bacteria sampler, between flow measurement device and borne bacteria sampler
Need not be fixed by fixture, using very convenient.
Apparatus of the present invention have the advantages that simple structure, low cost, certainty of measurement are high, are adapted to borne bacteria sampler and use enterprise
The mode that dispatches from the factory of the self-correcting, the calibration of third party testing agency and borne bacteria sampler production unit of industry.
The above is only the preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art
For member, under the premise without departing from the principles of the invention, some improvements and modifications can also be made, these improvements and modifications also should
It is considered as protection scope of the present invention.
Claims (10)
1. a kind of flow measurement device for borne bacteria sampler, it is characterised in that including deflector and testing agency,
The deflector includes baffle, the equal drift net of air (5), the first pressure tappings (2), the second pressure tappings (3) and orifice plate
(6), the baffle has flow-guiding channel, and the orifice plate (6) is arranged in the flow-guiding channel, the equal drift net of air (5)
The porch of the flow-guiding channel is arranged on, the outlet of the flow-guiding channel is used to connect the acquisition port of borne bacteria sampler, institute
State the first pressure tappings (2) and the second pressure tappings (3) are opened on the baffle and are connected with the flow-guiding channel, described
Between the equal drift net of the air (5) and the orifice plate (6), second pressure tappings (3) are positioned at the hole for one pressure tappings (2)
Between plate (6) and the outlet of the flow-guiding channel, the orifice plate (6) for make the first pressure tappings (2) and the second pressure tappings (3) it
Between produce pressure difference；
The testing agency includes air pressure difference sensor and flow rate conversion unit, and the air pressure difference sensor is used to detect institute
The air pressure difference between the first pressure tappings (2) and second pressure tappings (3) is stated, the flow rate conversion unit is used for the sky
The output signal of air pressure gap sensor process and obtains air mass flow, and a pressure interface of the air pressure difference sensor sets
First pressure tappings (2) are placed in, another pressure interface is arranged at second pressure tappings (3).
2. device according to claim 1, it is characterised in that the testing agency also includes being used for detection temperature and air pressure
In at least one physical quantity physical quantity detection element and for the output signal to the physical quantity detection element at
The Signal Processing Element of reason.
3. device according to claim 2, it is characterised in that the testing agency also includes being used for the air mass flow
And/or the output element (1) that the result of the Signal Processing Element is exported.
4. device according to claim 1, it is characterised in that the outer wall of the orifice plate (6) and the inwall of the baffle
Laminating, the axle center of the orifice plate (6) overlaps with the axis of the flow-guiding channel, and orifice plate (6) center has round hole, institute
The hole wall for stating round hole is vertical towards the end face of the equal drift net of the air (5) with the orifice plate.
5. device according to claim 4, it is characterised in that the baffle is hollow cylinder, cylinder it is hollow
Part is the flow-guiding channel, if the internal diameter of flow-guiding channel is D, then the orifice plate (6) is and the entrance of flow-guiding channel between
Vertical range is 2D, and vertical range of the orifice plate (6) and the outlet of flow-guiding channel between is D.
6. device according to claim 5, it is characterised in that between first pressure tappings (2) and the orifice plate (6)
Vertical range is D, and the vertical range between second pressure tappings (3) and the orifice plate (6) is D/2.
7. device according to claim 5, it is characterised in that set the orifice plate (6) center round hole it is a diameter of
D, then the scope of d/D is 0.3-0.7.
8. device according to claim 3, it is characterised in that the testing agency also includes that memory cell and amendment are single
Unit, the amending unit is connected with the memory cell and the flow rate conversion unit respectively, and the memory cell is used to store
Correction factor, the correction factor is corresponding with the value range of air mass flow, and the amending unit is used to determine that the flow is changed
Calculation cell processing obtains the correction factor corresponding to air mass flow, and the air mass flow is repaiied according to the correction factor
Just；
The amending unit is connected with the output element (1), and the output element (1) is additionally operable to export revised air stream
Amount.
9. device according to claim 1, it is characterised in that sealed step (4) is additionally provided with the outer wall of the baffle,
The sealed step (4) between the outlet of the second pressure tappings (3) with the flow-guiding channel, the sealed step (4)
Lower surface can be brought into close contact with the upper surface of the acquisition port.
10. device according to claim 9, it is characterised in that the outer wall of the baffle is provided with sealing ring, the sealing
Circle is located between the sealed step (4) and the outlet of the flow-guiding channel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710095178.2A CN106813758A (en) | 2017-02-22 | 2017-02-22 | A kind of flow measurement device for borne bacteria sampler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710095178.2A CN106813758A (en) | 2017-02-22 | 2017-02-22 | A kind of flow measurement device for borne bacteria sampler |
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| Publication Number | Publication Date |
|---|---|
| CN106813758A true CN106813758A (en) | 2017-06-09 |
Family
ID=59112717
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710095178.2A Pending CN106813758A (en) | 2017-02-22 | 2017-02-22 | A kind of flow measurement device for borne bacteria sampler |
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| Country | Link |
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| CN (1) | CN106813758A (en) |
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Application publication date: 20170609 |