I. Preparation and Status Confirmation Before Calibration
Power on the hot runner signal generator and preheat for at least 30 minutes to allow the internal crystal oscillator and analog circuitry to reach thermal stability and eliminate initial deviations caused by temperature drift.
Enter the device's System Settings menu and perform a self-test to confirm that all channels have no hardware errors and the device is functioning normally.
Disable all AM, FM, PM, and other modulation functions, and uniformly select a standard sine waveDC signal as the output waveform to avoid interference from additional signals during the calibration process.
Connect a process signal calibrator with an accuracy class ≥ ±0.01%, a high-precision frequency counter, and a multi-channel oscilloscope with a bandwidth ≥ 100MHz, and complete the preheating of the reference equipment.
II. Frequency Reference Recalibration
Set the signal generator output frequency to a typical value of 10MHz and use a high-precision frequency counter to measure the actual output frequency.
If the measured value deviation exceeds ±1ppm, enter the Frequency Calibration menu and adjust the Frequency Correction Factor until the deviation is zero.
The calibration process covers the commonly used 10kHz, 1MHz, 10MHz, and 100MHz frequency bands for hot runner verification, ensuring the clock reference accuracy meets the standards.
III. Output Amplitude Recalibration Set the output amplitude to 1Vpp (peak-to-peak value) and measure the actual output amplitude using an oscilloscope or high-precision multimeter.
If the deviation exceeds ±1%, adjust the Gain Correction Value through the Amplitude Calibration menu to eliminate the amplitude output error.
The calibration covers the commonly used 10mVpp, 100mVpp, 10Vpp, and 20Vpp amplitude ranges for hot runner verification. For high-amplitude calibration, enable the oscilloscope's high-impedance input mode (≥1MΩ) to avoid load effects introducing deviations.
IV. Thermal Signal-Specific Recalibration Thermocouple Signal Calibration Set the signal generator to output millivolt analog signals from commonly used thermocouples such as K-type and J-type. Using the millivolt measurement value of the process calibrator as a reference, adjust the thermocouple output correction coefficient to ensure the temperature simulation output accuracy matches the verification requirements of the hot runner temperature control channel.
RTD signal calibration Set the signal generator to output simulated resistance signals of commonly used RTDs such as Pt100 and Cu50. Using the resistance measurement value from the process calibrator as a benchmark, adjust the RTD output correction coefficient to ensure the simulated resistance output deviation is ≤ ±0.05%FS.
V. Multi-channel synchronous recalibration Using the rising edge of the main channel output waveform as a benchmark, simultaneously acquire the output signals of all slave channels using a multi-channel oscilloscope, and read the phase time difference between each channel and the main channel.
Enter the Delay Calibration menu for each channel, fine-tuning the channel delay correction coefficient until the synchronization deviation between all channels and the main channel is ≤0.01s.
If the synchronization trigger line length exceeds 200 meters, enable the equipment's cable resistance compensation function. Automatically calculate the transmission delay compensation based on the cable length and cross-sectional area to offset the synchronization deviation caused by long-distance transmission.
VI. Post-calibration verification and parameter solidification After all calibrations are completed, randomly select 10 calibration points across the full range and measure the output value one by one using a reference device to confirm that the accuracy deviation of all points is within the allowable range.
Run the equipment continuously for 30 minutes, collecting output accuracy and synchronization deviation data every 5 minutes to confirm no instability due to drift over time.
Save all calibrated frequency correction factors, gain correction values, thermal signal correction factors, and delay correction factors to the equipment's non-volatile memory. These parameters will not be lost after a power outage and restart.
Record all parameter values from this calibration to generate a calibration file, providing a comparison benchmark for subsequent periodic recalibrations.
