ENMET CD-1300-ST - Manual (Page 8)

CO
2
Sensor / Transmitter ENMET Corporation
6
4.2 Altitude Correction
The CD-1300-ST series is factory-calibrated for operation at sea level. When operated at higher elevations, the calibration
must be adjusted by the amount shown in the altitude correction table to the right.
Table 1: Altitude Correction
Altitude [ft] Multiplication
Factor
0 1.0
500 1.02
1000 1.03
1500 1.05
2000 1.07
2500 1.08
3000 1.10
3500 1.12
4000 1.14
4500 1.16
5000 1.18
4.2.1 Altitude Correction Procedure
To adjust the calibration of a unit currently calibrated for sea level operation to a new altitude proceed as follows:
1. Let the CD-1300-ST Series stabilize to the ambient CO
2
concentration, and record the reading in ppm.
2. Multiply the reading by the scale factor corresponding to the operating altitude in the altitude correction table. For instance if
the unit is operating at an altitude of 4000 ft, the scale factor from the table is 1.14. If the concentration reads 420 ppm,
multiply 420 times 1.14 giving 478 ppm. Adjust the display to read 480.
3. Remove the CD-1300-ST Series’ cover (see cover removal procedure on Section 3.1).
4. N OTE whether the shorting block at jumper JP5 is covering both pins or only a single pin, then borrow the shorting
block and slide it over the two pins of jumper JP2 (see Figure 2 Section 3.3). Use the 'UP' and 'DOWN' buttons to change the
concentration to the value just calculated.
5. Remove the shorting block from jumper JP2 and return it to its previous position over one or both pins of jumper JP5.
6. Replace the cover (see procedure on Section 3.4.1).
5.0 Calibration
This section describes the calibration verification procedure and calibration adjustment procedures.
5.1 Verification Procedure
A quick but approximate calibration verification can be done by supplying the unit with outside air and letting the reading
stabilize. CO
2
concentrations in outside air are typically between 350 and 450 ppm. A more accurate calibration check requires
the use of calibration gas of known concentration. Calibration materials are available from the factory or your local distributor.
Description ENMET part number
Regulator 02506-005
Cylinder CO
2
1000ppm 03223-1000
Cylinder CO
2
2000ppm 03223-2000
Cylinder CO
2
5000ppm 03223-5000