5-7
5
TABLE 5-2 TROUBLESHOOTING GUIDE
CONTINUED
Possible
Symptom
Fault
Action or Check
Bad Analog readings
Wrong range
Check range settings
Erratic values
Check filter setting
Noise on analog inputs
Add filter capacitors, shielding
Bad temperatures
Readings going
Check thermocouple polarity
wrong direction
Grossly inaccurate
Check thermocouple type
Reading drifiting
Insulate the thermocouple
circuits from ambient
changes.