Specifications
2008 Residential Appendices RA3-10
Appendix RA3 – Residential Field Verification and Diagnostic Test Protocols
RA3.2.2.1 Minimum Qualifications for this Procedure
Persons carrying out this procedure shall be qualified to perform the following:
1. Obtain accurate pressure/temperature readings from refrigeration gauges.
2. Obtain accurate temperature readings from electronic thermometer and temperature sensors.
3. Check calibration of refrigerant gauges using a known reference pressure
4. Check calibration of electronic thermometer and temperature sensors using a known reference
temperature.
5. Check calibration of electronic temperature thermometer and pipe temperature sensors using a pipe at a
known reference temperature in a surrounding atmosphere at least 40ºF different from the pipe
temperature.
6. Determine best location for temperature measurements in duct system and on refrigerant lines.
7. Calculate the measured superheat and temperature split.
8. Determine the required superheat and temperature split, based on the conditions present at the time of the
test.
9. Determine if measured values are reasonable.
RA3.2.2.2 Instrumentation Specifications
Instrum
entation for the procedures described in this section shall conform to the following specifications:
RA3.2.2.2.1 Digital Thermometer
Digital therm
ometer shall have dual channel capability in Celsius or Fahrenheit readout with:
1. Accuracy: ± (0.1% of reading + 1.3º F).
2. Resolution: 0.2º F.
RA3.2.2.2.2 Tempera
ture Sensors and Temperature Measurement Access Holes (TMAH)
Measurements require four (4) temperature sensors with a response time that produces the accuracy specified
in Section RA3.2.2.2.1 within 15 seconds of immersion in a bath at least 40º F different from the surrounding
conditions.
Measurements require one (1) cotton wick for measuring wet-bulb temperatures.
Measurements require at two (2) pipe temperature sensors that produce the accuracy specified in Section
RA3.2.2.2.1 within 15 seconds of being applied to a pipe at least 40º F different from the surrounding
conditions.
There shall be two labeled temperature measurement access holes, one in the supply plenum and one in the
return plenum. The temperature measurements shall be taken at the following locations: