Carrier TRANSICOLD PrimeLINE 69NT40-571-001, Руководство по эксплуатации и обслуживанию, Страница: 150 / 186

T-372 7–34
7. Replace wire ties that were removed. Replace shields and close the control panel door.
7.28 Temperature Sensor Service
Service procedures for the return recorder, return temperature, supply recorder, supply temperature, ambient, defrost
temperature, evaporator temperature, and compressor discharge temperature sensors are provided in this section.
7.28.1 Ice Bath Preparation
The ice-water bath is a method for testing the accuracy of sensors by submerging the sensors in an insulated
container with ice cubes or chipped ice, then filling voids between ice with water and agitating until mixture reaches
0°C (32°F) measured on a laboratory thermometer.
Notes:
• Wherever possible, use a thermometer that is regularly calibrated by an accredited test lab. Contact your
instrument representative if the reference thermometer is not showing correct readings.
• Always use a temperature measurement reference instrument which is of higher accuracy than the device
checked – for e.g., a thermometer with a rated accuracy of +/- 0.2 °C should be used to check a device with
a rated ac/- 0.3 °C.
• A thermally insulated container, tub open to atmosphere and large enough to contain crushed ice and water
should be used. The tub should be large enough to contain the unit’s sensor and the reference thermometer.
• Enough distilled water should be available to make ice cubes and to set up a proper and stable ice-water tri
-
ple-point mixture. Prepare ice using distilled water.
• Pre-cool distilled water for testing.
Procedure:
1. Prepare a mixture of clean ice using distilled water in a clean insulated container. If possible, the person
handling should be wearing latex gloves.
a. Crush or chip the ice to completely fill the container. Finer ice particles will produce a more accurate mixture.
b. Add enough pre-cooled distilled water to fill the container.
c. Stir the mixture for a minimum of 2 minutes to ensure water is completely cooled and good mixing has
occurred.
d. The mixture should generally contain about 85% ice with distilled water occupying the rest of the space.
e. Add more ice as the ice melts.
2. Stir the ice water slurry mixture to maintain a temperature 0°C (32°F).
3. Constantly monitor the temperature of the ice water slurry with your reference thermometer. Ensure that the
temperature of the bath has stabilized. The criterion for stability generally is to take two readings at 1 minute
intervals, and the two readings should give you 0°C (32°F).