System Performance Check

1. Connect gauges as shown.





2. Insert a dry bulb thermometer in the cold air outlet, and place the psychrometer (dry and wet bulb thermometer) close to the inlet of blower. Do not spill wet bulb water.
3. Test conditions:
- Avoid direct sunlight.
- Open engine hood.
- Open front doors and windows.
- Set the temperature control lever to COLD.
- Push the VENT and Recirculation buttons.
- Turn the fan switch to HI.
- Run the engine at 1,500 rpm.
- No driver or passengers in car.
4. After running the system for about 10 minutes under the above conditions, read the thermometer and pressure valve.

Performance Chart:

5. The performance of the system is satisfactory if the measurements are within the range bands shown on the Performance Chart.

Example, Measurements:
Intake temperature
(Wet bulb): 75°F (24°C)
(Dry bulb): 86°F (30°C) 50% humidity
Delivery temperature: 52.7°F (11.5°C)
Delivery pressure: 1600 kPa (232 lbs/in2)
Intake pressure: 170 kPa (25 lbs/in2)

Proper intake/delivery pressure, and temperature ranges are shown on the chart.

6. To Use Chart:
- Find your intake temperature across the bottom, and the relative intake and delivery pressures up the side.
- Lines drawn at right angles to your measurements should cross within the range bands on the graph.

NOTE:
- The graph (Inspection data) shows humidity between 20% and 80%, divided into intervals of 10%.
- The shaded area is the 30-50% range.
- Tolerance is +/- 10% when taking a reading.
- This means that if humidity is 40%, 30-50% is the tolerance range.