The calibration of a mass flow controller is a multi-step process aimed at ensuring the accuracy and reliability of the flow controller in terms of readings and outputs. Here isMass flow controllerThe specific method of calibration:

1、 Preparation of environmental conditions

Ensure a stable calibration environment, with temperature controlled at (20 ± 5) ℃ and humidity within the range of 45% RH~75% RH.

Avoid sudden changes in atmospheric pressure, vibration interference, and magnetic field interference.

2、 Equipment inspection and connection

Check whether the quality flow controller and its supporting equipment (such as standard flow meters, U-tube pressure gauges, stopwatches, digital multimeters, gas cylinders, etc.) are intact, and whether the range and accuracy meet the requirements.

Clean the pipeline to ensure confidentiality.

Correctly connect the gas cylinder, the tested controller, the standard flow meter, and the U-tube pressure gauge to ensure that there is no air leakage at each connection point.

3、 Calibration steps

1. Appearance and preliminary inspection:

Check whether the appearance of the controller is damaged, whether the buttons are normal, and whether the display screen is clear.

Turn on the power, preheat to the specified time (usually 15-30 minutes), observe whether the displayed flow value is zero, if not, perform a reset operation.

2. Pipeline connection and leak detection:

Select a standard flow meter with an appropriate range based on the flow range of the tested controller, and connect the air circuit.

Ensure that the interface is sealed without leakage, and for high-pressure gases, an air tightness inspection step should be added.

3. Zero point calibration:

Adjust while ensuring that there is no airflow passing through the entire flow path systemMass flow controllerThe internal zero potentiometer makes the flow reading on the digital display board zero.

4. Calibration of indication error:

Set multiple different flow points (such as 0%, 25%, 50%, 75%, 100% of full scale) by adjusting valves or flow meters.

Record the readings of the standard flowmeter and the tested flowmeter, and calculate the indication error.

Repeat measurements multiple times and take the average to improve accuracy.

5. Response time calibration:

Set a flow step change (such as from 0% to 50% or from 50% to 100%).

Simultaneously start the stopwatch and record the time required for the tested controller's response to reach stability.

The response time should meet the requirements of the technical specifications, otherwise internal parameters need to be adjusted or components need to be replaced.

6. Repetitive calibration:

Select 2-3 different traffic points for repeatability testing.

Measure each flow point multiple times (e.g. 6 times), record the readings, and calculate the repeatability error.

Ensure repeatability meets requirements to demonstrate the consistency and reliability of the controller.

7. Control performance calibration (if equipped with external control function):

Send control commands through external analog signals or communication interfaces.

Observe the accuracy and timeliness of the actions executed by the tested controller.

4、 Data recording and result judgment

Detailed records of various data during the calibration process, including flow set values, standard flow meter readings, tested flow meter readings, time, temperature, and other environmental conditions.

Determine whether the indicators such as indication error, repeatability, and response time of the tested controller meet the requirements of the technical specifications based on calibration data.

5、 Report preparation and archiving preservation

Organize calibration data and prepare calibration reports. The report should include information on the calibrated instrument, calibration basis, calibration items, calibration data, uncertainty/accuracy levels, calibration conclusions, and other related content.

Archive the calibration report for future reference and quality control.

6、 Special calibration methods (such as the calibration method in the invention)

In some cases, special calibration methods may be used, such as calculating the actual flow rate by collecting chamber pressure and comparing it with the set flow rate to determine the accuracy of the mass flow controller. This type of method usually involves complex calculation and measurement steps, requiring professional equipment and technical personnel to operate.

　　Mass flow controllerCalibration is a rigorous and meticulous process that requires strict adherence to operating procedures. Through calibration, the accuracy and reliability of the controller in terms of readings and outputs can be ensured, thereby improving the performance of the entire flow control system.