RKI Instruments Eagle Series - Manual (Page 88)

81 • Appendix J: Infrared Hydrocarbon Sensor Eagle Instruction Manual
Calibrating the Infrared HC Sensor
Recommended calibration frequency for the infrared HC sensor is
once every 3 months. Enter Calibration mode and calibrate the
infrared HC sensor using the same procedure as the standard
combustible gas sensor (see “Calibration” on page 42). Be sure to use
50% LEL isobutane to calibrate the infrared HC sensor, not methane. If
calibrating only an infrared HC channel, use a 50% LEL isobutane
cylinder and the single calibration method. If calibrating multiple
channels that include infrared HC, oxygen, CO, or H
2
S, use a 4-gas
mix calibration cylinder with isobutane and the auto calibration
method. If calibrating other channel types, use an appropriate
calibration cylinder and the single calibration method.
Adjusting the Sensor Controls
CAUTION: Only perform the following steps if you are unable to set the
correct calibration reading with the AIR/
▲ and SHIFT/ ▼
buttons.
1. Use the AIR/▲ and SHIFT/▼ buttons to set the reading to the
middle of the range in which you can currently adjust the reading.
For example, if you can set the reading from a minimum of 10%
LEL to a maximum of 40% LEL, set the display to 25% LEL.
2. Unscrew the two large screws on the top of the case, then carefully
lift the top of the case and lay it aside.
3. Locate the infrared HC sensor in the front half of the bottom case.
It is connected to the EC4 socket on the analog PCB.
4. Adjust the sensor’s SPAN control one turn and observe the
display reading. Continue to adjust the SPAN control until the
display reading matches the concentration of the calibration
cylinder.
The SPAN control is on the top edge of the amplifier and is the
control closest to the front of the instrument.
5. Place the top of the case in its original position, then secure it with
the large screws you loosened in step 5.
6. Continue with the normal calibration procedure.
4 Toxic gas or infrared carbon dioxide EC1, EC2, or EC3
Table 19: Sensor Configuration for Eagles with Infrared HC Sensors
Channel Sensor Analog PCB Socket