I. Warm-up and Self-Test
Power on the hot runner signal generator and allow it to warm up for at least 30 minutes to allow the internal crystal oscillator and analog circuitry to reach thermal stability.
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 wave as the output waveform to avoid additional signal interference during the calibration process.
II. Frequency Reference Calibration
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.
Complete the calibration covering the entire frequency range (1μHz to 200MHz), focusing on calibrating the commonly used 10kHz, 1MHz, 10MHz, and 100MHz frequency bands for hot runner verification.
III. Output Amplitude Calibration Set the output amplitude to 1Vpp (peak-to-peak)
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.
Coverage the commonly used amplitude ranges of 10mVpp, 100mVpp, 10Vpp, and 20Vpp for hot runner calibration. When calibrating high amplitude, enable the oscilloscope's high-impedance input mode (≥1MΩ) to avoid load effects introducing deviations.
IV. Waveform Distortion Calibration Output a 1kHz sine wave and use the oscilloscope's THD (Total Harmonic Distortion) measurement function to check the waveform distortion.
If the THD exceeds the specification of -60dBc, adjust the signal generator's "Waveform Optimization" parameters, such as filter bandwidth and waveform smoothing coefficient, to reduce waveform distortion.
If necessary, use an external distortion calibration kit for advanced correction to further optimize waveform quality.
V. Specific Calibration of Thermal Signals
Thermocouple Signal Calibration: Set the signal generator to output millivolt analog signals of commonly used thermocouples such as type K and type J. Using the millivolt measurement value of the process calibrator as a benchmark, adjust the thermocouple output correction coefficient to match the calibration accuracy requirements of the hot runner temperature control channel.
RTD Signal Calibration: Set the signal generator to output resistance analog signals of commonly used RTDs such as Pt100 and Cu50. Using the resistance measurement value of the process calibrator as a benchmark, adjust the RTD output correction coefficient to ensure that the resistance analog output deviation is ≤ ±0.05%FS.
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 data every 5 minutes to confirm that there is no instability due to drift over time.
Save all calibrated frequency correction coefficients, gain correction values, and thermal signal correction coefficients to the equipment's non-volatile memory. The parameters will not be lost after a power outage and restart.
Record all parameter values for this calibration, generate a calibration file, and provide a comparison benchmark for subsequent periodic recalibration.
