Electromagnetic flowmeter zero correction method

Case introduction

1. The significance of zero point correction of electromagnetic flowmeter

Electromagnetic flowmeter is a commonly used flow measurement instrument. In actual use, measurement errors may occur due to various reasons. At this time, it is necessary to Perform zero point correction to ensure measurement accuracy. The zero point of the electromagnetic flowmeter mainly refers to the static zero point, which is the voltage or signal value output when there is no flow. The zero point correction is used to ensure that the output value is zero.

2. Methods of zero-point correction of electromagnetic flowmeter

There are two main methods of zero-point correction of electromagnetic flowmeter: automatic correction and manual correction.

1. Automatic correction

Modern electromagnetic flowmeters are usually equipped with automatic zero correction function. When performing automatic correction, first keep the electromagnetic flowmeter in a closed state, then aim the sensor port of the flowmeter at a stationary place without fluid, turn on the power of the electromagnetic flowmeter, and enter the automatic zero point correction mode. At this time, the electromagnetic flowmeter automatically collects the interference signal of the sensor, adjusts the signal offset of the sensor according to the interference signal, and realizes automatic zero point correction. After completing the automatic correction, re-measure the fluid to obtain a more accurate flow value.

2. Manual correction

When the automatic correction function is abnormal or unavailable, you can choose to perform zero point correction manually. The manual correction process is relatively cumbersome and needs to be performed without fluid flowing through it. First, the accumulated error in the electromagnetic flowmeter is cleared, and then the electromagnetic valve is disconnected to stop the flow of fluid. Then open the electromagnetic flowmeter and adjust it to manual correction mode, manually setting the output signal to zero. After completing the manual correction, restart the flow measurement and judge whether the correction is successful based on whether the output signal is zero.

3. How to judge whether the correction is successful

The zero point correction of the electromagnetic flowmeter requires attention to some details. After the correction is completed, an acceptance inspection is required to determine whether the correction is successful. There are two main acceptance methods:

1. Read the output signal

After the correction is completed, read the output signal value to determine whether it is zero. If the output signal is zero, it indicates that the correction is successful.

2. Flow detection

Set the measurement range of the flow meter to a smaller flow range, flow the fluid through the electromagnetic flow meter, and observe whether the flow rate can be measured accurately. If it can be measured accurately, the correction is successful.

In summary, zero point correction of electromagnetic flowmeter is a necessary measure to ensure the accuracy of flow measurement. When performing zero point correction, attention should be paid to the correction method and acceptance method to ensure correct correction and accurate measurement.