Johnson Controls CDS-2000 Manual page 9

Full Calibration
Equipment Needed
Procedure
S Sensors and Stats—CDS-2000 CO
• a digital voltmeter with 10 mVDC resolution and a range of at least
0 to 10 VDC
• a small (0.07 in. or less), flat-blade jeweler's screwdriver
• a small, non-metallic probe for accessing the pushbuttons
• a source of dry nitrogen gas from which all CO
(0 ppm)
• a source of air with a known concentration of 2000 ppm
(±40 ppm) CO
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• a regulator that can maintain flow between 400 and 800 ml/min.
(24 to 48 SCIM)
• a silicone blanket and tubing
Use the following procedure only when it is necessary to completely reset the
sensor's offset and span.
!
CAUTION: Make sure bottled gas at 2000 ppm CO
1. Connect the Digital Voltmeter (DVM) between Terminal 8 (+) and
Terminal 2 (-) on the terminal block (back of the unit). Power up the
unit.
2. Allow the CDS-2000 approximately one hour to warm-up. In the
first few minutes of the warm-up, the green LED on the front of the
unit below the sensor will remain dark. After a few minutes, the green
LED will flash continuously, which indicates that the unit is in the
Primary mode. The unit will be ready for verification once the one-
hour warm-up period is over. (The green LED will still be flashing.)
3. Using a non-metallic probe, press and hold down the recessed
SW-1 button until the green LED gives three quick flashes and goes
dark; then, immediately release the button. The unit is now in the
Calibration mode, and the LED remains off.
4. Press and hold down the SW-2 button (to the right of SW-1, see
Figure 1) until the LED gives three quick flashes and a momentary
dark pause; then, immediately release the button to switch the unit into
the Full Calibration mode (LED will be flashing continuously).
at 0 ppm CO concentration is available before
2
beginning calibration. The previous span setting is
automatically erased when the Full Calibration Mode
procedure is initiated.
Sensor Verification, Calibration, and Troubleshooting Bulletin 9
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has been removed
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and a bottle
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