Specifications

Calibration
5.8 Calibrate NX
(For PCA Models 30, 35, 60 & 65)
PCA
The Nitric Oxide sensor needs to be spanned at regular intervals to
determine if the analyzer still meets its accuracy specification. Because of
the toxicity of Nitric Oxide gas, however, unless your facility has the
necessary gas cylinders and personnel trained in the handling of toxic
gases, we recommend that the Nitric Oxide sensor be spanned by an
authorized Bacharach Service Center.
Material Required:
• Calibration Gas Fixture (Section 5.2)
• Gas Cylinder, 50 to 150 ppm Nitric Oxide with an analytical
accuracy of ±1% ( c u stomer supplied)
Procedure:
1. Enter the Calibrate Menu Screen per Section 5.3. Then choose to
calibrate the NX sensor.
2. At the conclusion of Step 1 the pump should start running.
3. Using the Gas Fixture shown in Figure 5-1, attach the Nitric Oxide
calibration-gas cylinder to the analyzer’s GAS inlet.
4. Adjust the regulator of the calibration fixture for a flowmeter indica-
tion of approximately 2 SCFH.
5. Wait until the MEASURED reading on the screen stabilizes (approxi-
mately 3 minutes). Then use the st and ENTER keys to enter an
APPLIED value* that equals the concentration that is stamped on the
NX calibration-gas cylinder.
Typical Calibrate NX Screen During Calibration,
Using 100 ppm Nitric Oxide Calibration Gas:
CALIBRATE NX
MEASURED 092 PPM
APPLIED 0100 PPM
6. Press the RUN key to calibrate the analyzer’s MEASURED value to that
of the APPLIED value. At this time the Calibrate Menu Screen is
redisplayed.
* The NX calibration range is 50 – 150 ppm. Any attempt to calibrate
outside range will cause the analyzer to display the message BAD
CALIBRATION ENTRY.
5-8 Instruction 0024-9219