General Tools and Instruments CDM77535 - Manual (Page 9)

TROUBLESHOOTING
? CAN’T POWER ON
Press ( ) for more than 0.3 seconds and try again. Check
whether batteries are in good contact with correct polarity, or the
adapter is plugged in properly.
? FIXED READINGS
Check whether data hold function was activated. (HOLD icon at the
top left)
? SLOW RESPONSE
Check whether the airflow channels on the rear are blocked.
? ERROR MESSAGES
E01: CO
2
sensor damaged
E02: The value is under range
E03: The value is over range
E04: The original data error results in this error (DP, WB)
E07: Too low a voltage to measure CO
2
. Replace batteries or use
the adapter
E11: Retry humidity calibration
E17: Retry CO
2
calibration
E31: Temperature sensor damaged
E34: Humidity sensor damaged
PC CONNECTION
The meter can do PC link for on-line logging and data analysis via
RS232 interface and software.
The protocol is as follows:
A. 9600 bps, 8 data bits, no parity.
B. Format (ASCII)
Cxxxxppm:Txxx.xC(F):Hxx.x%: dxxx.xC(F):wxxx.xC(F) LRC CRLF
Description: $CO2:Air:RH:DP:WBT LRC CRLF
CDM775355-final-092508:Layout 1 9/25/08 10:11 AM Page 9