Calibration of soap film flowmeter

Calibration of soap film flowmeter

I. Overview

1purpose

Soap film flowmeter (hereinafter referred to as flowmeter) is a flowmeter used to measure the flow rate of small gases. It can be divided into direct reading glass tube soap film flowmeter (hereinafter referred to as soap film flowmeter) and soap film flowmeter with a pair of electronic sensors installed on the soap film tube (hereinafter referred to as electronic soap film flowmeter). The direct reading glass tube soap film flowmeter generally has a maximum flow rate of 12L/min. electricity

The soap film flowmeter generally has a maximum flow rate of 60L/min. When the soap film flowmeter needs to be used as a device, it should comply with the relevant provisions of Appendix B.

2. Structural type

The soap film flowmeter is a soap film tube with a scale, and there is an air inlet under the soap film tube. The bottom of the soap film tube is connected to a rubber ball, which contains soap film liquid. The electronic soap film flowmeter is equipped with a lower limit sensor and an upper limit sensor on the outer wall of the soap film tube, and is equipped with a display instrument.

The structure of the soap film flowmeter is shown in Figure 1.

The structure of the electronic soap film flowmeter is shown in Figure 2.

3. Working principle

As shown in Figure 1 and Figure 2, the working principle of the soap film flowmeter is that the gas flowing out from the gas source is adjusted to the required flow rate through a flow control valve, and then enters the soap film tube through the inlet at the lower end of the soap film tube, squeezing the rubber ball (or using other methods) to produce a soap film. Due to the pressure of the inlet, the soap film is pushed up along the soap film tube at a constant speed. When the soap film rises to the soap film tube

When the bottom line is marked, the timer starts counting. When the soap film rises to the top line of the soap film tube, the timer stops counting. The instantaneous flow rate through the flowmeter can be calculated based on the measured time and the volume between the two lines of the soap film tube. The electronic soap film flowmeter, on the other hand, uses a pair of sensors installed on the outer wall to measure the lower and upper limits during the rising process of the soap filmXian timeThe display instrument directly shows the instantaneous flow rate. The display instrument can also show the set parameters (such as volume, temperature, atmospheric pressure, etc.).

4. Measurement performance requirements

4.1 Accuracy level and maximum allowable error

The accuracy level and maximum allowable error of the flowmeter should not exceed the specifications in Table 1.

4.2 Repeatability

The repeatability of the flowmeter should not exceed half of the maximum allowable error specified in Table 1.

5. Calibration instruments and equipment

5.1Calibration of soap film flowmeterPlease refer to the table below for the instruments and equipment used.

5.2Calibration of electronic soap film flowmeterPlease refer to the table below for the instruments and equipment used.

The above is the relevant content of soap film flowmeter. The measurement performance indicators of flow meters generally include flow range, accuracy level, and maximum allowable error, etc. These parameters should be clearly indicated on the device or explained in the user manual.