Detcon IR-642 - Manual (Page 7)

T50 < 15 seconds; T90 < 35 seconds
Clearing Time
90% < 35 seconds
Repeatability
± 3% FS
Range
0 - 0.3/0.5/1/2/3/5% withthe IR-640
0-10/0-25/0-50/0-100% with the IR-642
Operating Temperature
-40° to +175° F
Accuracy
± 5% FS
Sensor Warranty
5 year pro-rated
Power Consumption
Normal operation = 95 mA (2.3 watts); Full alarm = 123 mA (<3 watts)
Zero Drift
< 0.05% per year
Output
3 relays (alarm 1, alarm 2, and fault) contact rated 5 amps @ 250 VAC, 5 amps @ 30 VDC;
Linear 4-20 mA DC; RS-485 Modbus™
Input Voltage
22.5-28 VDC
3.4 O PERATING S OFTWARE
Operating software is menu listed with operator interface via the two magnetic program switches located under the
face plate. The two switches are referred to as “PGM 1” and “PGM 2”. The menu list consists of 3 items which
include sub-menus as indicated below. (Note: see the last page of this manual for a complete software f low chart.)
01. Normal Operation
a) Current Status
02. Calibration Mode
a) Zero
b) Span
03. Program Menu
a) Program Status
b) Alarm 1 Level
c) Alarm 2 Level
d) Calibration Level
3.4.1 Normal Operation
In normal operation, the display tracks the current status of the sensor and gas concentration and appears as:
“0.00 % CO2”. The mA current output corresponds to the monitoring level and range of 0-100% FS = 4-20 mA.
3.4.2 Calibration Mode
Calibration mode allows for sensor zero and span adjustments. “1-ZERO 2-SPAN”
3.4.2.1 Zero Adjustment
Zero is set in ambient air with no CO2 gas present or with zero gas applied to the sensor. “AUTO ZERO”
3.4.2.2 Span Adjustment
Unless otherwise specif ied, span adjustment is performed at 50% of full-scale range of CO2. “AUTO SPAN”
Detcon Model IR-640/IR-642 Carbon Dioxide Sensor PG.7