Published: 2025-06-30 Article source:
Hello everyone! Welcome to General Measure's channel. Today, we'll explain how to calibrate the flow of the loss-in-weight controller GMC-X3.
A loss-in-weight controller is a device used to accurately control the feeding rate of materials, particularly bulk solids, by precisely measuring the weight loss of the material over time.
The GMC-X3 can be operated directly or connected to an HMI. Here we will explain how to do the flow calibration on the HMI.
The flow calibration of the GMC-X3 has two methods, manual calibration and automatic calibration, involving the parameter settings such as analog, flow value, and calibration switch. Before the flow calibration, it is necessary to ensure that there is sufficient material in the silo.
First, we set the parameters related to flow calibration
1. Material Parameter Settings
Before calibrating the flow, we need to set the low level, high level, flow unit, and flow decimal point.
Low-Level Setting
The device will start feeding when the weight is below the low level value.
The low level is usually set to about 10% of the full silo weight.
High-Level Setting
The device stops feeding when it reaches a high level value.
The high level is usually set at about 80% of full silo weight. And make sure it is larger than the low level.
Flow Unit Settings
To ensure flow accuracy, the flow unit should be consistent with the weight unit.
As we set the weight unit as kg, here the flow unit is selected as kg/h.
Flow Decimal Point
To ensure flow accuracy, the decimal point for flow should be consistent with the decimal point for weight.
Here, we select three decimal points (0.000) as we did in weight calibration.
The above settings are for manual flow calibration. If you choose automatic flow calibration, you must also set the automatic calibration delay and the calibration interval delay.
Auto-Calibration Delay
Auto-calibration delay is the duration of a single calibration analog output during auto-calibration.
In actual flow calibration, you need to adjust this value according to the time from startup to flow fluctuation stabilization.
Calibration Interval Delay
Calibration interval delay is the duration of the interval when the analog output of the next calibration point is executed.
In the automatic calibration interface, click the calibration interval delay. Here, set the calibration interval delay to 5 seconds, and click confirm to save it.
2. Flow Calibration Process
After setting the material parameters, we move on to the flow calibration demonstration. Make sure the scale is free from external interference to avoid affecting the accuracy of flow calibration.
Flow calibration can be manual calibration or automatic calibration.
Manual Calibration
Manual calibration has 4 calibration points.
The analog setting of the calibration point is usually related to the current selected analog working type. For example, if the selected analog output 1 is 4-20mA, the calibration analog is evenly divided into 4 segments: 8mA, 12mA, 16mA, 20mA. Here, set the analog at point 1 to 8mA. Then start the flow calibration of point 1. If the weight is less than the Low Level, a feeding prompt will appear on the flow calibration interface. After feeding is completed, the flow calibration at point 1 will continue.
Return to the main interface to view the flow. The real-time flow will be recorded in the flow value at point 1 every 3 seconds. When the flow fluctuation stabilizes, click the calibration button at point 1 again to complete the calibration.
We recommend doing all four points of calibration to make sure the flow can run smoothly in each interval. Follow the above steps to finish the calibration of the other three points.
If it is not the first time for flow calibration, by filling in the analog and corresponding flows recorded at each of the four points, the flow calibration will be completed.
Auto-calibration
Enter the flow calibration interface, click on automatic calibration.
If analog are set to the four calibration points, the automatic calibration will output the analog in sequence according to the set values. For example: point 1 is set to 8mA, point 2 to 12mA, point 3 and point 4 are not set, the instrument's automatic calibration values will only calibrate the first and second points, then finish the process. If the analog is not set, the calibration analog will be automatically assigned to the calibration points 1 to 4 according to the working type of the analog.
Click the auto-calibration button to start, then go back to the main page
Return to the automatic calibration interface to view the data corresponding to the calibration point. A linear increase in the data from point 1 to point 4 means the flow calibration is completed.
3. Verify the linearity of the Flow Calibration
After the flow calibration is completed, start the instrument to verify that the flow calibration linearity is correct. Set the target flow rate to 20kg/h and starting running. Then you need to calculate whether the analog output corresponding to 20kg/h is linearly consistent with the flow calibration. (Note: For example, 8mA analog corresponds to 10kg/h flow, 20kg/h analog should correspond to about 12mA). If the results are consistent, it indicates that this flow calibration is successful.
That's all for the flow calibration. In the next video, we will introduce the bus communication of the GMC-X3.