I. Preparation before verification: Confirm that the thermal engineering tool (analog signal generator for hot runner systems) is in normal working condition, with an accuracy class ≥ ±0.05%FS, meeting the accuracy requirements for channel verification.
Disconnect the field sensor circuit of the channel to be verified. Directly connect the output terminal of the signal generator to the input terminal of the hot runner temperature control channel to avoid interference from field sensors.
II. Standard signal output and acquisition verification: Through the analog signal generator, sequentially input three standard DC current signals of 4mA, 12mA, and 20mA to the channel, covering the full range of 4~20mA industrial standard signals.
Observe the displayed values of the corresponding channels in real time on the monitoring interface of the hot runner temperature control system, and record the system display value corresponding to each input current.
III. Channel qualification judgment: Calculate the percentage of the system display value relative to the range and compare it with the theoretical percentage corresponding to the input current (4mA corresponds to 0%, 12mA to 50%, and 20mA to 100%). If the displayed numerical deviation is ≤ ±0.5%FS, and corresponds exactly to the input current value, the hot runner analog signal channel can be determined to be normal, and the verification is passed.
IV. Final Reset After verification, disconnect the signal generator from the channel terminals, reconnect it to the original field sensor circuit, and confirm that the channel signal has returned to normal, completing the full-process channel verification.
This verification method is fully adaptable to the field operation and maintenance scenarios of hot runner temperature control systems. It is simple and efficient to operate, and can accurately complete channel verification without complex equipment.
