CN2349549Y

CN2349549Y - Liquid flow tester

Info

Publication number: CN2349549Y
Application number: CN 96217874
Authority: CN
Inventors: 王华伸
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-08-04
Filing date: 1996-07-16
Publication date: 1999-11-17
Anticipated expiration: 2006-07-16

Abstract

The utility model discloses a liquid flow measuring device which comprises a differential pressure transmitter (1), a single chip computer unit (2), a keyboard (3) and a display unit (4). On the basis that the corresponding relationship exists between the differential pressure and the lift, and between the lift and the flow of both ends of a liquid pump, the liquid flow is measured by measuring the pressure difference of both of the two ends of the liquid pump. Compared with the prior art, the pipeline installing place of the utility model is the installing place of the liquid pump; therefore, the utility model has the advantages of accurate measurement, no flow rate requirement, no straight-pipe section requirement and convenient installation. The utility model can be used for measuring and metering various occasions which can not satisfy the straight-pipe section requirement and the flow rate requirement.

Description

The fluid flow pick-up unit

The utility model relates to the measurement of flow, particularly a kind of device of measuring fluid flow.

At present, the device of measuring fluid flow is a lot, as electromagnetic flowmeter, turbo flow meter, vortex shedding flow meter, ultrasonic flow meter etc.Though the each have their own characteristics of these devices in use all have some common defects: the firstth, must be installed on the straight length, the duct section that promptly is mounted must be a straight tube, the straight length that needs is tens meters long usually; Second has requirement to the flow rate of liquid in the pipeline exactly, can not be too low, otherwise precision is influenced.To the requirement of straight length and flow velocity, caused great inconvenience for the use of said apparatus.

The purpose of this utility model is: provide a kind of measurement accurate, easy for installation, the installation site is not had the straight length requirement, to the liquid flow measurement device of flow velocity no requirement (NR).It is that two ends pressure reduction according to the liquid pump all has corresponding relation with lift, lift with flow, and the pressure reduction at the two ends by measuring the liquid pump is handled through single machine unit and obtained lift signal and flow signal.

Formation of the present utility model: the single machine unit (2) that comprises the differential pressure transmitter (1) of measuring liquid pump pressure difference, the output signal of differential pressure transmitter (1) is handled.

Described single machine unit (2) can be connected to keyboard (3).

Described single machine unit (2) can be connected to display unit (4).

Compared with the prior art, the utility model by obtaining the lift signal in the pressure measurement of the two ends of liquid pump, passes through its corresponding relation of COMPUTER CALCULATION owing to be according to liquid lift of pump and flow corresponding relation to be arranged again.Piping erection of the present utility model place is just in the installation place of liquid pump, therefore have measure accurately, no flow velocity requirement, no straight length requirement, advantage easy for installation, can measure, measure the various occasions that do not satisfy straight length requirement or flow velocity requirement.

Below in conjunction with accompanying drawing embodiment of the present utility model is described in further detail.

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is one of electrical schematic diagram of the present utility model: single machine unit (2) part.

Fig. 3 is two of an electrical schematic diagram of the present utility model: other parts.

Embodiment: the single machine unit (2) that formation of the present utility model comprises the differential pressure transmitter (1) of measuring liquid pump pressure difference, the output signal of differential pressure transmitter (1) is handled.

Described single machine unit (2) can be connected to keyboard (3).

Described single machine unit (2) can be connected to display unit (4).

The utility model is to have corresponding relation to measure according to liquid lift of pump and flow, during work, the pressure reduction of surveying the pump two ends by differential pressure transmitter (1) obtains the lift of pump signal, send into single-chip microcomputer behind the A/D translation interface of this signal in single machine unit (2), single-chip microcomputer becomes corresponding flow signal by program stored and form among the EPROM in the single machine unit (2) with the lift conversion of signals.The simulating signal of delivery rate behind the D/A translation interface of single-chip microcomputer in single machine unit (2); The digital signal of delivery rate simultaneously directly, the instantaneous value that digital signal can delivery rate also can be exported accumulated value as required.Flow signal send display unit (4) to show or record.Can adjust operational factor and software, selection measurement unit by keyboard (3).For different pump types, the relation between its lift and flow is different, can realize the variation of its corresponding relation by the conversion form in the change software.

What differential pressure conversion was here exported directly is the lift of pump signal.Also can survey the pressure signal at pump two ends by two pressure units respectively, then signal is sent the single machine unit computing to obtain lift signal and flow signal, only be to use two A/D translation interfaces, promptly the output terminal of each pressure unit respectively links to each other with an A/D translation interface.The digital quantity of display unit (4) shows it is that LED shows, also can adopt the digital quantity of other modes to show; Analog quantity registering instrument record also can adopt other analog quantity display modes.

In the present embodiment, single-chip microcomputer adopts 8031 single-chip microcomputers, EPROM adopts 2764, A/D conversion is made up of DAC0832 and 5G24 and comparer, it is a software A/D translation interface, D/A conversion delivery outlet is made up of DAC0832 and 5G24, and digital quantity is exported behind the driving amplifying circuit that phototriode LD, triode BG1BG2 form.

In the present embodiment, record water pump pressure at two ends difference by differential pressure transmitter (1), and output corresponding simulating amount current signal (0～10mA), this current signal converts analog quantity voltage signal (0～5V) and send into A/D conversion mouthful to through signal converter (10mA/5V), mouthful to be a software A/D conversion mouthful is made up of DAC0832D/A converter and 5G24 and comparer for A/D conversion in this example, adopts successive approximation method to finish A/D by the software in the single-chip microcomputer and changes.A/D conversion back input 8031 single-chip microcomputers, single-chip microcomputer through tabling look-up and computing, draws data on flows by the program among the operation EPROM (2764), transfers outlet output analog signals VOUT through D/A again, through driving amplifying circuit output digital quantity signal.Differential pressure transmitter in use may carry out verification, needs to compensate adjustment after the general survey, compensation rate can be imported 8031 by the keyboard (3) that 2 74LS245 and dial switch are formed.Also can adopt the mode of changing EPROM (2764) chip to compensate adjustment.Display unit (4) is made of ER-180 registering instrument and 446 message registers, and wherein analog quantity outputs to the ER-180 registering instrument, and digital quantity outputs to 446 message registers.

Claims

1, liquid flow measurement device is characterized in that: form the single machine unit (2) comprise the differential pressure transmitter (1) of measuring liquid pump pressure difference, the output signal of differential pressure transmitter (1) is handled.

2, liquid flow measurement device according to claim 1 is characterized in that: described single machine unit (2) is connected to keyboard (3).

3, liquid flow measurement device according to claim 1 and 2 is characterized in that: described single machine unit (2) is connected to display unit (4).