ENMET ISA-44-RALE-OD User Manual
Page 22
ENMET Corporation
ISA-44RALE-OD/ISA-44RAHE-OD/ISA-44E-OD
18
7. While the gas is flowing through the sample head assembly, the carbon monoxide channel meter inside the control
unit should indicate an increasing level of CO. When the meter reaches the low alarm point range (+ or - 2 meter
needle widths of the low alarm point) the amber CO alarm LED should be on. When the meter reaches the high
alarm point range (+ or - 2 meter needle widths of the high alarm point), the red CO alarm LED should be on. When
the meter reaches full scale, the CO channel rough test is complete.
8. Shut off the valve of the calibration fixture. Do not remove the fixture until the air flow meter on the sample head
assembly reads zero. If you remove the fixture before this, back pressure may shoot water onto the sensor and cause
damage.
9. When the pressure gauge of the sample head assembly reads zero, remove the calibration fixture from the air inlet of
the sample head assembly. To do this, hold the calibration fixture in place, pull back on the metal collar of the quick
release fitting and carefully remove the calibration fixture from the air inlet.
10. Remove the calibration fixture from the cylinder of 75 ppm CO, and attach it to the cylinder of 17.0% oxygen.
11. Using the O2 gain control knob adjust the O2 reading to 20.9.
12. Repeat steps 5-6.
13. Watch the meter and red alarm LED of the oxygen channel. The red oxygen alarm LED should activate between
19.6 and 19.4% oxygen. If the instrument is equipped with a factory installed horn, it will also activate.
N
OTE
: The CO sensor may respond when the 17% O2 is applied. This in normal.
14. Repeat steps 8 and 9.
15. Reconnect the sample head assembly to the compressed air line. Rough test is complete. If instrument passes Rough
Test, instrument is ready for operation. If instrument fails Rough Test, proceed to calibration section 6.0.
5.2 Rough Test ISA-44E-OD
This test simulates a gas alarm condition to verify the unit's response capability.
1. Hold a butane lighter near the sensor cover.
2. Very briefly depress the lever, without striking the flint, to squirt some butane vapors, to trigger the alarm.
N
OTE
: This method is best for units set primarily for hydrocarbon responses. Many units which are set to respond to toxic
gases or vapors require calibration gas to verify the response capability. See section 6.3.1 routine gas test.