PROBE CERTIFICATION


OXYGEN PROBE CERTIFICATION PROGRAM

United Process Controls’ probe certification program is designed to maximize the life of a probe and ensure the most accurate readings possible. All probes are tested in a certified atmosphere against a probe standard and must meet deviation criteria.

Our program includes the following evaluation techniques:


Mechanical Inspection
Each probe is carefully inspected for condition by a skilled UPC technician. Any indications of soot, contamination, fatigue, chemical attack and any other mechanical problem are noted and recommendations are provided based on the "“as found"” condition of the probe.

Millivolt (sensor output) measurement in a certified atmosphere
Probe millivolt output is measured in a certified atmosphere and compared to a reference standard.

Certification contains reference standard reading, allowable deviation, actual reading, and pass/fail result.

Probe thermocouple verification
Probes are tested at 1750ºF (954ºC) against a certified standard.

Certification contains reference standard reading, allowable deviation, actual reading, and pass/fail result.

Impedance Testing
Impedance testing is a long-accepted, standard method for the indication of probe condition. This test clearly assesses the health of the probe’s electrode contact.

As a probe ages, the millivolt output and recovery time are affected by minute soot particulates in the electrode interface, or by mechanical and contamination issues with the electrode interface.

For this test, the millivolt output of the sensor is compared to the reading taken prior to the test.

Recovery Testing
With time and usage, it’'s possible for the zirconia electrolyte of the probe to destabilize and for the electrode contact to deteriorate.

Recovery time of the millivolt reading before and after the impedance test provides an excellent indication of these conditions.

Leak Testing / Reference air flow verification
During the test, the sensor is placed in the furnace atmosphere and the reference air supply is disconnected. If there’s a leakage in the probe electrolyte, the millivolt output would drop beyond the tolerance limit.


UPC offers instrumentation & accessories that can automatically perform some of these tests in-situ.

PROTHERM 455
PROTHERM 500/600 or 700