Det-Tronics NTMOS IP66/IP67 H2S Gas Detector - Manual (Page 8)

95-8670 2.1 6
STARTUP PROCEDURE
WARNING
Ensure that any output loads actuated by
the detection system are bypassed to prevent
accidental or unnecessary activation of these
devices.
1. Apply power to the system.
2. Remove the (red) protective cap and desiccant bag
from the detector.
NOTE
Transmitters and display/control devices
typically have a “warm‑up” period to allow the
detector to stabilize before beginning normal
operation (the NTMOS Detector can remain
in warm‑up for up to 30 minutes). After long
periods without power, the detector output may
still not have returned to zero ppm by the end
of the warm‑up period. In some cases, an alarm
level of H
2
S may be indicated. Keep all output
loads that are actuated by the system in bypass
until all alarms clear.
3. Allow the detector to operate for 16 to 24 hours
prior to an initial calibration , then perform the
“Calibration Procedure" as described in the following
section. It may be necessary to refer to other
transmitter and/or controller manuals to complete
calibration.
4. Complete any additional startup/commissioning
requirements as described in the manual provided
with the transmitter/control device.
5. Place the system in normal operation.
CALIBRATION
FREQUENCY OF CALIBRATION
The calibration frequency required in different
applications can vary depending upon the amount of
background gas, concentration of H
2
S, and ambient
environmental conditions.
Calibration must be performed:
— When a new system is initially put into service.
— When the detector is replaced.
— If a transmitter, controller or other device used in
conjunction with the NTMOS Detector is replaced.
The following calibration/bump test schedule is
recommended to ensure reliable operation in most
applications:
1. 24 hours after initial power-up (initial calibration)
2. 30 days after initial calibration
3. 60 days after initial calibration
4. 90 days after initial calibration
If all recommended calibration/bump tests are within
the acceptable limits, the tests can be performed
at (maximum) 90-day intervals thereafter. If large
adjustments occur (greater than 10%), calibration
intervals should be reduced.
CALIBRATION GAS
The NTMOS H
2
S detector must be calibrated using the
humidification tube with bottled H
2
S in air (Figure 7), or
with the ampoule calibration kit.
HUMIDIFICATION TUBE KIT
(Includes cage and tubes)
A2503
CAL CUP
REGULATOR
BOTTLED H
2
S
GAS IN AIR
Figure 7—Humidification Tube Assembly