Oldham OLCT 200 User Manual page 39

Use the following step-by-step procedure to perform ZERO and SPAN calibrations.
1. To enter the CAL MODE from either data display, press the DOWN / CAL key
and within 5 seconds press the EDIT key. Note: During CAL MODE, the
follow signal is transmitted to the receiving device and signifies "CAL MODE".
This special value is used to inhibit alarm trips at the receiver.
2 Wire Model
3mA
FOR OXYGEN (O2), SKIP STEPS 2 & 3 AND PROCEED DIRECTLY TO
THE SPAN CALIBRATION BY PRESSING THE "NEXT" KEY.
2. Using the Cal-Cup, apply a clean ZERO gas or be sure there is no
background target gas in the monitored area. After the reading is stable,
(approximately 1 minute) press the EDIT key to perform a ZERO calibration.
3. If the ZERO calibration is successful, press the NEXT key to proceed to the
SPAN check.
4. Apply the correct SPAN gas at .5 liters/min. After the reading is stable,
(approximately 1 minute) press the EDIT key to perform a SPAN calibration.
WARNING: The SPAN gas used must match the value specified since this is
what the OLCT 200 will indicate after a successful SPAN calibration. The Cal
Span Value may be edited if it becomes necessary to apply a different gas
concentration (see Cal Span Value in section 5.3).
If the SPAN calibration is successful, the display flashes "REMOVE CAL
5.
GAS" and starts the CAL PURGE delay. Note: During CAL PURGE delay,
transmitters are set to 0% full scale to avoid unintended alarm events.
Oxygen monitors are set to 20.9% oxygen during this delay.
6. CAL MODE will be complete after the end of the CAL PURGE delay.
The flow chart in Figure 4-2 illustrates the above procedure. UP, CAL, NEXT & EDIT
labels indicate keystrokes using the magnetic wand. The CAL MODE information
screen (top of the chart) is available for advanced users to see Offset / Gain calibration
constants and live analog to digital converter (A/D) counts. Span Gas calibration
values may also be edited from this screen. Holding the UP key, for 5 seconds during
CAL MODE, displays this screen.
Calibration history records are logged and may be viewed in the Sensor Information
menu (see section 5-5).
3 Wire Model
1.5mA
OLCT 200 User Manual | 39
10-30VDC
Wireless Model
75 counts
(-15.6%FS)
Battery Powered
Wireless Model
75 counts
(-15.6%FS)