Servomex DF-310E, Operator'S Manual

Page: 97 / 130

Troubleshooting and Calibration DF-310E 93
9 Troubleshooting and Calibration
9.1 Return Material Authorization Number
If an analyzer has to be returned to the factory, the shipper will have to obtain a Return Material
Authorization number from Servomex by calling the local Business Center. See the Shipping
Section on page 103 for more details.
9.2 Maintenance
The analyzer maintenance recommendations made in this manual apply to all Analyzers being
operated under Normal Operating Conditions and in clean gas applications.
A clean gas application is one in which certain process conditions are met. The sample
background gas must contain less than 10% of the acid gas limits shown in Table 2 page 33, on a
continuous basis. Solvents or other gases that are listed as “very soluble” to “infinitely soluble”
in water must make up less than 0.1% of the background gas composition. Sample condensation
must be avoided. For a hydrocarbon background gas, the sample must be kept at a temperature
of at least 40°F over the sample dewpoint. A wet sample (high water dewpoint) must be kept at
a temperature of at least 10° F over the dewpoint. The particulate density must be below the
limit of 0.03 mg/L (weight of particulate matter / volume of sample at atmospheric pressure).
Some examples of clean gas applications include monitoring of high purity gas pipelines,
compressed cylinder gases, cryogenic air separation plants, polyolefin feedstocks, glove boxes,
and semiconductor process tools.
9.2.1 Calibration
All Servomex DF-310 E Process Oxygen Analyzers are calibrated with NIST (National Institute
For Standards And Technology) traceable certified gas standards at the factory prior to shipment.
No initial calibration is required upon receipt from the factory.
For Analyzers used in clean gas applications (as described above) and operated under Normal
Operating Condition
s , Servomex recommends verifying the span calibration every 12 months of
continuous use. This can be accomplished by using the Analyzer to read a gas sample with a
known concentration, such as a certified cylinder gas mixture of O
2
in N
2
background, available
from any specialty gas supplier. For process applications containing more significant quantities
of acid gases or particulate, or where liquids may be encountered, contact Servomex for a
recommendation on calibration verification for your specific case.
For Analyzers used in clean gas applications, and operated under Normal Operating Conditions
there is no need for zero calibration checks in the field.