Zero And Span Calibration For Xnx Ec Sensors; Zero And Span Calibration Of Xnx Ec Hydrogen Sulfide - Honeywell XNX Quick Start Manual

WARNING
While XNX is in Inhibit Mode, alarms are silenced. This will prevent an actual gas event from being
reported. Inhibit Mode must be reset after testing or maintenance activities.

8.1.2 Zero and Span Calibration for XNX EC Sensors

CAUTION
Before initial calibration, allow the detector to stabilize for 30 minutes after applying power. When
in zero and span calibration mode, the current output from the detector is inhibited (default 3mA) to
avoid false alarms.
It is recommended for most sticky gases (i.e.: HCl, Cl
of rubber tube to make the final connection due to the inflexibility of PTFE. This minimizes adhesion
of the gas to the tube surface and allows for more accurate measurement.
Recalibration is recommended if the temperature of local environment has varied by more than +/-15
degrees C from the temperature of calibration.
EN performance standards require 10 minutes stabilization time for application of zero and span gas
for performance-approved EC, mV, and IR sensors prior to calibration..
To calibrate the detector, use an appropriate span gas cylinder, flow regulator
set to 300-375mL/min, tubing, magnet and calibration gas flow housing. A
compressed gas cylinder (20.9%Vol oxygen) should be used to perform the zero
calibration if the area where the detector is located contains any residual amount
of the target gas. If no residual gas is present then the background air can be
used to perform the zero calibration. Contact your HA representative for details of
suitable calibration kits.
To calibrate the detector follow the procedure in Section 8.1.1.
NOTE:
The Oxygen sensor does not require a zeroing procedure. Background air
(20.9%Vol oxygen) can be used to span the oxygen sensor in place of a
compressed air cylinder (20.9%Vol oxygen).
See section 6.3.2 of the XNX Technical Manual for other EC sensors.
8.1.3 Zero and Span Calibration of XNX EC Hydrogen Sulfide (H
CAUTION
Before initial calibration, allow the detector to stabilize for 30 minutes after applying power. When
in zero and span calibration mode, the current output from the detector is inhibited (default 3mA) to
avoid false alarms.
Recalibration is recommended if the temperature of local environment has varied by more than +/-15
degrees C from the temperature of calibration.
Hydrogen Sulfide sensors can be affected by extreme humidity changes. A
XNX Universal Transmitter Quick Start Guide
Figure 48. Exiting options
) the tubing should be PTFE with short pieces
2
S) Sensors
2
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