Based on the previous focus on the need to verify temperature measurement accuracy through freezing point benchmark calibration after correcting mismatched hot runner thermocouple calibration numbers, the specific operational steps for freezing point benchmark calibration are as follows:
Preparing a Standard Freezing Point Environment: Prepare crushed ice from distilled water and place it in an insulated container. Slowly add a small amount of distilled water while stirring to form an ice-water mixture, ensuring the mixture is in equilibrium at 0°C. Cover the container to reduce interference from ambient temperature.
Treating the Thermocouple Cold Junction: Disconnect the compensating leads of the thermocouple to be calibrated from the hot runner end. Fully insert the thermocouple's cold junction probe into the ice-water mixture, avoiding the container walls and ice, ensuring it is completely submerged in the ice-water interface area.
Station and Reading Recording: Allow the temperature to stand for 3-5 minutes until it stabilizes completely. Then, read the displayed temperature of the temperature control chamber. The normal value should be stable within the range of 0±1°C. Repeat the verification process: After removing the cold end and allowing it to sit at room temperature for a short while, reinsert the ice-water mixture and repeat the verification twice more. Confirm that the deviations in all three readings are within the allowable range to complete the accuracy verification.
Throughout the entire operation, an insulated container must be used to isolate the ambient heat source to prevent the ice-water mixture from rapidly heating up and affecting the verification accuracy.
