Instruction and operating guideline CO-detector
Type:
VCD2 CO-Detector
7
1. Connect loop power to the transmitter.
2. Apply clean air or an inert gas to the transmitter for 2 minutes.
3. Hold down the program button until the LED flashes at approximately 1 Hz.
The 4 mA level is now set.
4. Apply the required span gas to the transmitter for 2 to 5 minutes.
5. Press and release the program button. The 20 mA level is now set to
represent the concentration of the calibration gas used.
6. The LED will flash at approximately 8 Hz for 8 Seconds. This is the timeout
period.
7. Calibration is complete. The LED will clear and the transmitter will return to
normal mode.
Non-Standard Span Gas Calibration Methods
Span Gas Within ±5% of Full Range
1.
Calculate the mA signal expected for span gas. The output range available
is 19.2 mA to 20.8 mA.
Example
Required 4-20 mA range is 0-500 ppm
Available span gas is 480 ppm
Dynamic Range is 16 mA
Therefore, 1 mA = 31.25 ppm
Expected signal at 480 ppm = (15.36 mA + 4 mA) = 19.36
mA
2. Connect loop power to the transmitter.
3. Apply clean air or an inert gas to the transmitter for 2 minutes.
4. Hold down the program button until the LED flashes at approximately 1 Hz.
The 4 mA level is now set.
5. Apply the required span gas to the transmitter for 2 to 5 minutes.
6. Press and hold the program button to set the 20 mA level.
7. The LED will flash at approximately 8 Hz for 8 Seconds. Continued momentary
pressing of the program button during this timeout period will increase the
output by 40
μΑ
per press. When the output reaches 20.8 mA, the next button
press will take the output to 19.2 mA. Further button presses will again increase
the output by 40
μΑ
When the required output is reached, allow the transmitter
to time out.
8. Calibration is complete. The LED will clear and the transmitter will return to
normal mode.
