Operating instructions

AMC-210 Transmitter with external electrochemical sensor
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4 OPERATION AND CALIBRATION
4.1 OPERATION
The AMC-210 series sensor/transmitter is factory calibrated for the gas listed in section 2.2 at
the beginning of this manual. The sensor/transmitter should not need re-calibration when first
installed and powered up, but a test for correct operation is recommended after a stabilization
period of 10 minutes.
Following stabilization, the sensor/transmitter should be sending (in a Zero Gas environment) a
4 mA signal to the monitor or controller (except oxygen). However, there are a few situations
where a slightly higher or lower than normal signal may be noticed. In many facilities there can
be residual levels of the gas being detected in the air at all times. These can cause a minor
response from the sensor expressed as a rise in signal. Other causes for minor signal
variations include extremes in temperature. The application of a clean air sample will verify if
the elevated signal is from background gas or equipment error.
Although the electrochemical sensors are very selective, there are some interference gases,
which can also cause a response from the sensor. These gases are listed on the detailed
Specifications sheet pertaining to the sensor in use available from AMC.
4.2 CALIBRATION
The transmitter is equipped with a remote calibration feature allowing one-man calibration at the
sensor/transmitter location. The transmitter output is measured using a plug-in type “Remote
Calibration Lead” (P/N 2900-01) designed to be adaptable to most multimeters. Zero and Span
adjustments are made at the transmitter. Recalibration is necessary when replacing the sensor.
Verification of calibration should be done at least once every 6 months. For safety reasons and
highly demanding applications, monthly verification is recommended.
Factory/on-site calibration services, customer training and/or calibration adapter are available.
Specify the sensor/transmitter Part Number & Serial Number listed in section 2.1
SENSOR/TRANSMITTER and refer to section 2.2 FACTORY CALIBRATION for Gas Type and
calibration adapter when ordering any of the above.
Caution:
- Only qualified personnel should perform the actual calibration.
- Users are advised to consult The Armstrong Monitoring Corporation as to the
calibration procedure and recommended gas concentration for the application.
For some exotic gases, calibration standards needed for field calibration are not readily
available. The Armstrong Monitoring Corporation offers the following calibration plans:
1. Factory pre-calibrated replacement sensor/transmitter units
2. On site installation and calibration by Armstrong Monitoring
3. On site calibration by Armstrong Monitoring
4. Training by Armstrong Monitoring