In order to prevent additional calibration problems caused by temperature variations, turn on the device and warm it for at least half an hour. This will allow the internal analogue circuitry to fully stabilise thermally.
Create a reference process calibrator that has an accuracy class of at least ±0.01%. As a traceability baseline for accuracy comparison, its accuracy class needs to be at least two classes higher than the signal generator undergoing calibration.
Make sure all test cables are securely fastened. Make sure the gadget is consistently grounded. Electromagnetic interference should be eliminated by maintaining a constant temperature of 23±5°C and a humidity level of no more than 80%.
Step 1: Basic Self-Test and Zero-Point Calibration: To ensure that the device is operating normally and free of hardware problems, navigate to the signal generator system settings menu and choose the "Self-Test" function.
Leave the signal generator output port empty and disconnect all external loads. Choose "Zero-Point Calibration" from the system calibration menu.
Await the device to automatically zero the zero-point deviation correction and obtain the true zero-point output value under the current unloaded state. Verify that the output deviation at zero is less than 0.01% of the range.
Step 2: Full-Range Accuracy Calibration and Basic Self-Test and Zero-Point Calibration
Using a reference calibrator, measure the actual output value point-by-point after setting the signal generator output sequentially to 10%, 25%, 50%, 75%, and 100% of the range.
To ensure that the full-range output deviation is below the nominal accuracy of the equipment, eliminate nonlinear variations across multiple ranges by adjusting the gain correction coefficient of the appropriate channel for each range.
Particular Thermal Signal Calibration: To rectify temperature analogue signal errors and satisfy the hot runner temperature control channel's calibration criteria, calibrate the thermocouple millivolt output and RTD resistance output point-by-point.
Frequency calibration involves setting the output frequency of the signal generator to 10MHz, using a high-precision frequency counter to measure the actual output frequency, adjusting the frequency correction coefficient until the deviation is zero, and concentrating on calibrating frequently used frequency bands throughout the whole frequency range.
Waveform Distortion Calibration: Produce a 1 kHz sine wave, use an oscilloscope in THD mode to evaluate the waveform distortion, modify the waveform optimisation parameters, and make sure the THD does not beyond the technical limitations of the apparatus.
Step 3: Archiving and Post-Calibration Verification
Run the system continuously for an hour after calibration, gathering output data from important verification points every ten minutes to ensure that there is no continuous offset and that the drift is less than 0.03% of the range.
To ensure that there are no signal jumps or communication disruptions and that the difference between the temperature control system display value and the signal generator output value is ≤±1℃, connect to the hot runner temperature control system and run a full-channel linkage test.
The device is prepared for official use once all verification items satisfy the requirements, the calibration parameters are saved to the non-volatile memory of the device, and a calibration record is created for archiving.
In order to ensure that the hot runner signal generator's calibration accuracy satisfies production line standards, this simple and straightforward calibration process can be carried out independently by regular industrial control system maintenance experts without the need for additional sophisticated gear.
