Forma Scientific 3546 - Page 41

Forma Scientific, Inc._____________________________________________Service
6-2
Symptom Possible Cause
Problem 7: Digital CO
2
display and
FYRITE read more than 1% different from
setpoint. CO
2
alarm not on.
• Alarm is disabled.
• Defective alarm circuit.
• Defective CO
2
sampler or control.
Problem 8: CO
2
display and FYRITE read
0% CO
2
. Setpoint is OK. CO
2
alarm is
activated. CO
2
inject light is on.
• Loss of CO
2
supply.
• Defective CO
2
solenoid.
• Clogged CO
2
in-line filter.
Problem 9: CO
2
display shows some
random number or decimal point.
• Defective readout board.
• Defective output to readout board from
CO
2
control.
• Faulty interconnecting wiring.
Problem 10: CO
2
display will not go to
zero no matter how long the door is left
open.
• Improper procedure. Close door and allow
temperature and RH to stabilize eight
hours.
• Defective CO
2
sensor.
• Defective CO
2
control.
Problem 11: Display flickers badly or
counts up and down three or four digits.
• Defective readout board.
• Excessive electrical interference near the
cabinet.
• Faulty grounding circuit.
• Sampler blower is improperly installed or is
defective.