Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N1/00—Sampling; Preparing specimens for investigation
  • G01N1/02—Devices for withdrawing samples
  • G01N1/22—Devices for withdrawing samples in the gaseous state
  • G01N1/2202—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling
  • G01N1/2208—Devices for withdrawing samples in the gaseous state involving separation of sample components during sampling with impactors
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
  • G01N15/10—Investigating individual particles
  • G01N2015/1024—Counting particles by non-optical means

Definitions

• the present invention relates to an apparatus for the microbiological and particle sampling of a gas existing in atmosphere.
• the apparatus according to the present invention will be continued to be referred to with the tradename "DualCapt ® ". Furthermore, the hardware and software features thereof will be illustrated.
• the apparatus according to the present invention is able to perform, in a wholly autonomous way, microbiological and particle samplings.
• the apparatus according to the present invention comprises:
• an autonomous particle counter/sampler able to manage the information related to the sampling by means of a serial line RS485 MODBUS RTU.
• the technical specifications of the particle counter/sampler will be not described hereinafter as they are already known in the art.
• microbiological sampler or impactor, managed by an electronic control board which will be described in details.
• the apparatus provides: ⁇ an impactor, for example of the Biocapt ® type;
• the pneumatic line shows an inlet section, for sucking the gas to be analysed.
• DualCapt is a microbiological and particle sampler operating by means of centralized vacuum and controls RS485 MODBUS RTU.
• the apparatus is constituted by two different types of samplers enclosed into a single case: ⁇ lmpactor Biocapt (which is wholly managed by the hardware and software described hereinafter);
• the aim is to obtain a single apparatus able to perform, in a wholly free or simultaneous way, the biological and particle sampling in the position wherein it is installed or, by means of isokinetic probe for the particle sampling, and extension with plant impactor for the microbiological sampling, in remote position (maximum 3 metres) with respect to the installation place.
• figure 1 is a functional scheme of the apparatus according to the present invention
• figure 2 is a scheme of a "DualCapt" connector used in the present invention
• figures 3 to 9 are electrical schemes of the control board of the apparatus according to the present invention
• figure 10 is a schematic view of the LED plate of the apparatus
• figures 11 to 17 are mechanical drawings of the apparatus according to the present invention
• figures 18 and 19 illustrate some installation modes.
• FIG. 1 shows the functional scheme of the apparatus.
• the function of the electronic control board is to manage wholly the microbiological sampling and partially the particle sampling.
• the board manages the opening and closing of first means for intercepting the flow interposed, along the pneumatic line, between said inlet section and said microbiological sampler and comprising, by way of example and not for limitative purposes, an EV1 interception electrovalve.
• the particle sampling is performed by a wholly autonomous particle counter. If the two (particle and microbiological) samplings have to be managed simultaneously, and by using one single data line, one single pneumatic line and one single power supply, the function of the electronic control board, as far as the particle sampling is concerned, is to intercept the start and stop commands sent to the particle counter, by means of the configuration of ID2 address of the board (the board has two ID addresses: a microbiological address: ID1; and a particle address : ID2), to be configured equal to the one of the particle counter.
• the board allows to connect the modbus line and the particle counter power supply to a connector.
• the microbiological sampler is characterized by a critical orifice OC, calibrated so as to allow sampling 28,7 l/min.
• the check of the sampling sonicity is guaranteed by pressure measuring means, comprising an absolute pressure sensor PA which measures the pressure downwards the critical orifice and it verifies that it is lower or equal to 47 Kpa, so as to guarantee that the measured sampling flow be equal to the one defined by the critical orifice.
• Said absolute pressure sensor PA measures the real atmospheric pressure to determine the real sucking flow, considering that for the principle of the critical orifice, the flow measurement is directly proportional to that of the barometric pressure. That is, being the pneumatic conditions equal, the sea level measurement results to be greater than the high altitude one.
• the sampler guarantees the maximum quality independently from the altitude.
• the correct measurement of the sucking flow determines a greater precision of the sampled volume.
• the electronic board is equipped with a microprocessor able to perform the described operations and with a firmware for managing data.
• the board has not clocks, that is a datary able to manage date and time, but a timer the function thereof is to count the seconds which have passed as from a known instant.
• the electronic board has a jumper (Jumper JP2) which allows changing the logic of the biological sampling.
• Joper JP2 Upon closing the circuit, the logic of the microbiological sampling is excluded and only the opening and closing of the EV1 electrovalve is managed, as it happens for the logic of the particle sampling.
• the microbiological sampler is able to receive information related to the configuration (Input Data), and to provide information related to the sampling and to the apparatus (Output Data).
• Both input and output data are managed by means of the serial line RS485 Modbus RTU. Therefore, the sampler can operate only if it is connected to a SCADA software or the like.
• Pneumatic connection rilsan tube inner diameter 10 mm, outer 12 mm
• Number of fractionations from 1 to 99, 1 equals to a sampling without fractionations
• Gauge pressure Zero: from 0 to 350 Kpa * 10
• Microbiological start Sampling start; Opening of the EV1 electrovalve.
• Microbiological stop Sampling stop; Closing of the EV1 electrovalve.
• Particle start Opening of the EV2 electrovalve.
• Particle stop Closing of the EV2 electrovalve.
• N.B The values which are expressed in x * 10 show that the value is expressed as integer but to say the truth it has a decimal. Let's make an example: the value 352 KPa (x * 10) to say the truth will have to be transformed by the software into 350 / 10 that is: 35.2 KPa.
• the programming and measuring information from the instrument field are managed by means of a data line: Modbus RTU RS485.
• the instrument has a 4-pin connector placed backwards, schematically illustrated in figure 2.
• the pin configuration of the connector is the following:
• the apparatus is power supplied by a 20 VAC (20 -24 VAC max) 1.5A voltage by means of 2 wires. This voltage is used to power supply:
• the system according to the present invention is constituted by two distinct samplers enclosed into a single case.
• the case is made of stainless steel AISI 316L
• the operation logic of the two samplers is wholly autonomous both in the configuration and in the sampling phase.
• microbiological sampling unlike the particle one, interrupts automatically as soon as the set volume is reached.
• the logic is the following: ⁇ Reading of the atmospheric pressure;
• the electronic board has a jumper JP2 which allows managing the board in the actuator mode. That is, if the jumper is present (closed circuit), when the particle counter/sampler and/or the microbiological sampler are switched on, the board manages only the relays without the microbiological sampling logic.
• the electronic control board function is to intercept the Start and Stop commands and to open and close the EV2 electrovalve. All other commands are managed directly by the particle counter.
• Alarm Checks The microbiological sampler generates some alarms. During the sampling the following alarms are detected:.
• the counting time of the alarm intervention zeroes.
• the other alarms detected by the sampler are those linked to the general status of the system, that is the malfunction of one of the following devices:
• the apparatus according to the present invention manages also possible black-out situations. Obviously the black-out is interesting only if it intervenes during the sampling.
• both the particle counter and the electronic board remember the last activation state: Switched-off or Switched-on.
• the particle counter and the electrovalve state of the particle counter return to the original state. For example: if the particle counter was switched-on and therefore the electrovalve was open, if the power supply is interrupted, upon the return of the same, the particle counter switches-on and the electrovalve opens.
• the behaviour must be different. If during the sampling step a black out intervenes, the sampling is interrupted. Upon the power supply return, the sampling is not reset.
• Front panel The sampler's front panel is characterized by two series of leds which underline the logic status of the microbiological and particle sampling.
• ⁇ Power it shows that DualCapt control board is power- supplied.
• ⁇ Sampling On: The microbiological sampling is being performed.
• ⁇ Count flash: it shows that the particle counter is counting.
• Laser Status on: The particle counter's laser is operating correctly.
• Inlet section connector (inlet centralized vacuum)
• the critical orifice characterization has been made experimentally based upon the kind of used material.
• the critical orifice used for the microbiological sampler is composed as follows:
• the barometric pressure is not influent since, before performing the real sampling, the instrument performs the measurement of the barometric pressure whereas as reference temperature it utilizes a constant equal to 17,094 (19,2°C).
• the capacity calculation the following formula is used:
• ⁇ Q is the measured capacity
• ⁇ a is the characterization constant of the critical orifice
• Pa is the barometric pressure measured before the sampling
• ⁇ Pd is the load drop onto the line during the sampling
• ⁇ 17.094 is the temperature constant at 19.2 0 C.
• the apparatus according to the present invention further comprises means for calibrating the pressure sensors.
• the calibration module of the absolute and differential pressure sensors allows performing the alignment of the values based upon calibrated reference instruments.
• ⁇ aPa Absolute pressure Zero
• ⁇ xPa Absolute pressure angular coefficient
• ⁇ bPa Absolute pressure offset
• ⁇ MPd measurement of the Gauge pressure
• ⁇ aPd Gauge pressure Zero
• ⁇ xPd Gauge pressure angular coefficient
• ⁇ bPd Gauge pressure offset
• Gauge pressure aPd - xPd.
• the WIPa value must be the one really measured by the absolute pressure sensor.
• the MPd value must be the one really measured by the differential pressure sensor.
• the calibration data can be entered only if the following procedure is performed after the instrument switch-on.
• This procedure re-sets the previous calibration parameters and sets the default values. In this way the values of calibrated pressure coincide with those really read by the sensors.
• Serial command ID, 3,0,0x82,0, 1 ,CRC.
• ID 3,0,0x82,0, 1 ,CRC.
• the value is transmitted onto the serial port and stored in xPa2.
• the setting of the default parameters must be made if the instrument is re- programmed and the registers' value is at full-scale. This procedure is performed automatically by the processor and it does not require any intervention by the operator.
• MlWiMMiTjdllflM.MM instrument 3 0 0x6A 0 OxB x x Registers' Reading Note: DATA1 and DATA3 must be compulsory 0 otherwise an EXCEPTION CODE 3 will be generated.
• VOLH-L It expresses in hexadecimal (16 bit) the quantity of volume sampled in liters (at time of reading). When the instrument is not operating, the value is fixed to zero.
• FLOWH-L It expresses in hexadecimal (16 bit) the average flow. The data are expressed in (Kpa * 10). When the instrument is not operating, the value is fixed to zero.
• FCHJ- expresses in hexadecimal (16 bit) the fraction of the sampling in progress. When the instrument is not operating, the value is fixed to zero.
• CNTDHJ- expresses in hexadecimal (16 Bit) the time remaining after the pause (between the fractions) completion. When the instrument is not operating, the value is fixed to zero.
• PAHJ- It expresses in hexadecimal (16bit) the reading of the absolute pressure. The data are expressed in (Kpa * 10).
• VOLimpH_ L It expresses in hexadecimal (16 bit) the quantity of volume set in liters.
• FCimpHJ FCimpHJ. It expresses in hexadecimal (16 bit) the set sampling fractionations.
• DATA3 and DATA4 include the hexadecimal value to be programmed into the register VOLUME TO BE SAMPLED
• the admitted value ranges between 1 and 9000 liters and therefore the maximum value assumed by the pair DATA3JDATA4 is 0x2328.
• Different values generate an EXCEPTION CODE 3.
• the DATA1 byte must be 0 otherwise an EXCEPTION CODE 2 will be generated.
• DATA1 and DATA2 include the hexadecimal address to be read.
• DATA3 and DATA4 include the hexadecimal value to be programmed into the register FRACTIONATIONS.
• the admitted value ranges between 1 and 99 and therefore the maximum value assumed by the pair DATA3_DATA4 is 0x0063.
• Different values generate an EXCEPTION CODE 3.
• the DATA1 byte must be 0 otherwise an EXCEPTION CODE 2 is generated.
• DATA1 and DATA2 include the hexadecimal address to be read.
• DATA3 and DATA4 include the hexadecimal value to be programmed into the register PAUSE BETWEEN FRACTIONATIONS.
• the admitted value ranges between 1 and 7200 and therefore the maximum value assumed by the pair DATA3 DATA4 is 0x1 C20.
• Different values generate an EXCEPTION CODE 3.
• the byte DATA1 must be 0 otherwise an EXCEPTION CODE 2 is generated.
• DATA1 e DATA2 include the hexadecimal address to be read.
• DATA3 and DATA4 include the hexadecimal value to be programmed into the register ABSOLUTE PRESSURE ZERO.
• the admitted value ranges between 1 and 1200 and therefore the maximum value assumed by the pair DATA3_DATA4 is 0x04B0.
• Different values generate an EXCEPTION CODE 3.
• the byte DATA1 must be 0 otherwise an EXCEPTION CODE 2 is generated..
• DATA1 e DATA2 include the hexadecimal address to be read.
• DATA3 and DATA4 include the hexadecimal value to be programmed in the register ABSOLUTE PRESSURE SPAN.
• the admitted value ranges between 1 and 1200 and therefore the maximum value assumed by the pair DATA3_DATA4 is 0x04B0.
• Different values generate an EXCEPTION CODE 3.
• the byte DATA1 must be 0 otherwise an EXCEPTION CODE 2 is generated.
• instrument 6 0 0x82 - SpanPaH SpanPaL crch crcl DEVICE FUNCTION DATA1 DATA2 DATA3 DATA4 CRCL CRCH COMMAND/FUNCTION instrument 3 0 0x82 1 Reading Absolute pressure SPAN
• DATA1 e DATA2 include the hexadecimal address to be read.
• DATA3 and DATA4 include the hexadecimal value to be programmed in the register GAUGE PRESSURE ZERO.
• the admitted value ranges between 0 and 350 and therefore the maximum value assumed by the pair DATA3_DATA4 is 0x015E.
• Different values generate an EXCEPTION CODE 3.
• the byte DATA1 must be 0 otherwise an EXCEPTION CODE 2 is generated.
• DATA I e DATA2 include the hexadecimal address to be read.
• DATA3 and DATA4 include the hexadecimal value to be programmed in the register GAUGE PRESSURE ZERO.
• the admitted value ranges between 0 and 350 and therefore the maximum value assumed by the pair DATA3_DATA4 is 0x015E.
• Different values generate an EXCEPTION CODE 3.
• the byte DATA1 must be 0 otherwise an EXCEPTION CODE 2 is generated.
• DATA1 e DATA2 include the hexadecimal address to be read.
• DATA3 and DATA4 include the hexadecimal value to be programmed in the register SONICITY ALARM DELAY.
• the admitted value ranges between 1 and 60 and therefore the maximum value assumed by the pair DATA3J3ATA4 is OxOO3C.
• Different values generate an EXCEPTION CODE 3.
• the byte DATAl must be 0 otherwise an EXCEPTION CODE 2 is generated.
• DATA1 e DATA2 include the hexadecimal address to be read.
• instrument 3 2 RitalmH RitalmL crch crcl
• FIGS 3 to 9 are electrical schemes of the control board of the DualCapt apparatus.
• FIGS 11 to 17 are constructive mechanical drawings of the apparatus according to the present invention, shown by way of example.
• figures 18 and 19 show some of the installation and connection modes of the electronic control board.
• the present invention has been sofar described according to a preferred embodiment thereof shown by way of example and not for limitative purposes.

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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
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• Molecular Biology (AREA)
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• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Sampling And Sample Adjustment (AREA)
• Apparatus Associated With Microorganisms And Enzymes (AREA)

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• 2006
  • 2006-06-14 IT IT000312A patent/ITRM20060312A1/it unknown
• 2007
  • 2007-06-13 CN CN200780026780.5A patent/CN101495615A/zh active Pending
  • 2007-06-13 WO PCT/IB2007/052238 patent/WO2007144835A2/en active Application Filing
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