Honeywell XNX User Manual

XNX Universal Transmitter Quick Start Guide
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suddenincreaseinambienthumiditycanresultinashort-termpositivedriftinthe
instrument’sreading.Asuddendecreaseinambienthumiditycanresultinashort-
termnegativedriftintheinstrument’sreading.Thesearemostlikelytobenoticed
duringcalibrationwithdryorcylindergas.
When calibrating Hydrogen Sulfide cartridges the following should be taken into
account while following the procedure in Section 8.1.1:
1. Tozerothesensor,useacompressedgascylinderof20.9%Vol
oxygen(notNitrogen).Donotusebackgroundair.
2. Ifaspancalibrationistobeperformed,thespancalibrationgasshould
beappliedtothesensorimmediatelyafterthezeroingprocedure.Donot
allowthesensortoreturntoambientairconditions.
8.1.4 XNX EC Sensor Operational Life
Typical life of a toxic gas sensor is dependent on the application, frequency
and amount of gas exposure. Under normal conditions, with a 3 month visual
inspection and 6 month test/re-calibration, the toxic sensor has an expected life
equal to or greater than the lifetime as listed below:
• 12monthsforAmmoniaandHydrogenFluoridesensors.(SeeAmmonia
notebelow.)
• 24monthsforChlorineDioxide,Oxygen,andothertoxicsensors.
CAUTION
Oxygen decient atmospheres (less than 6%V/V) may result in inaccuracy of reading and
performance.
NOTE:
Ammonia electrochemical cells are reliable and suitable for applications where
no background concentration of ammonia exists. Under these conditions the
cells are expected to operate for 12 to 24 months.
These ammonia cells are of the consumptive type. Their operating life can be
adversely aected by continuous or excessive exposure to ammonia, or by
prolonged exposure to high temperatures and moisture.
To ensure continued detection availability, it is recommended that the detectors
are regularly bump tested and a relevant cell replacement program be
implemented.
8.1.5 Zero and Span Calibration for MPD Sensors
CAUTION
Extended or frequent exposure to elevated concentrations of combustible gases
may aect sensor sensitivity. Verify sensor performance by frequent calibration.
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.

Honeywell XNX Specifications

General

Brand	Honeywell
Model	XNX
Category	Transmitter
Language	English