Detcon DM-200 - Manual (Page 14)

Model DM-200
DM-200 Instruction Manual Rev. 2.0 Page 10 of 40
3. Operation
Operating software is menu listed with operator interface via the two magnetic program switches located under
the enclosure cover. 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 section 8 for a complete software flow chart.)
01. Normal
Operation
a) Current Status
02. Calibration Mode
a) Zero Cal
b) Span Cal
03. Program
Mode
a) View Program Status
b) Set Span Level
c) Set Date
3.1 Normal Operation
In normal operation, the display tracks the current status of the sensor and gas concentration and appears as:
“0 PPM xxx” (the “xxx” is the abbreviated gas type, i.e., “0 PPM H2S”) or for oxygen “20.9 % O2”. The mA
current output corresponds to the monitoring level of 0-100% of range = 4-20 mA. If applicable, the second
line of the display will show current “Fault” conditions.
3.2 Calibration Mode
Calibration mode allows for sensor zero and span adjustments. “1-Zero Cal, 2-Span Cal”
Zero Adjustment
Zero is set in ambient air with no target gas present or with zero gas applied to the sensor. “Auto Zero”
For oxygen, zero is performed with 100% nitrogen test gas applied.
Span Adjustment
Span adjustment is performed with a target gas concentration of 50% of range in balance of air or nitrogen.
Span gas concentrations other than 50% of range may be used. Refer to section 3.3 for details. “Auto Span”
For oxygen, span is set in normal ambient air or with test gas containing 20.9% O2 applied to the sensor.
3.3 Program Mode
The program mode provides a program status menu (View Program Status) to check all operational
parameters. It also allows for the adjustment of the auto span gas level setting and the current calendar date.
View Program Status
The view program status scrolls through a menu that displays the following information (the slash means the
data shown is on line two of the display). The information shown is an example of a typical status display.
1. The sensor type. The menu item appears as: “Sensor Type / CO”
2. The sensor range of detection. The menu item appears as: “Sensor Range / 0-100 PPM”