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Calibration
Overview - Periodic calibration of the Model 9002 is recommended to
maintain optimum accuracy throughout the life of the sensor. Sensor
calibration can be verified or re-established at any time by using a
reference device. Appropriate reference devices include:
• A recently calibrated hand-held dew point sensor, or
• Flowing a zero calibration gas through the sensor.
Calibration using this technique will re-establish the sensor to its original
factory calibration curve. GE Telaire offers the model 2076 calibration
kit, which provides a zero calibration gas, certified to have less than 0.1
grains/lb of water vapor content, and is ideal for this purpose.
Infrared sensors are unique as in that sensor drift occurs at the zero point
of the sensor calibration and not the span concentration; therefore, span
calibration of the sensor is not required.
Refer to the model 2076 calibration kit manual for additional
information.
Calibration Description - The sensor provides the following two
choices for calibration:
• Single Point Calibration
• Zero Point Calibration
Each method adjusts the zero setting of the sensor. Only one of these
methods should be used for calibration.
Single Point Calibration
This calibration mode allows the user to calibrate the sensor in ambient
air to a known concentration as measured by a recently calibrated
reference device (e.g., a hand held sensor which displays dew point or
grains). This type of calibration will ensure that the greatest sensor
accuracy is provided at or near this concentration used for calibration.
This type of calibration is particularly recommended if high accuracy of
the sensor is required over a narrow range of operation (e.g., clean
rooms). To perform this calibration, you must be confident that the
reference device you are using has been recently and properly calibrated.
The calibration kit is not necessary to perform a Single Point
Calibration.
Zero Point Calibration
This calibration mode allows the user to calibrate the sensor to a verified
zero concentration of water vapor. The display may not indicate 0.0
during the calibration process, which is normal.
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Calibration Procedure
Use of cellular telephones or radio transceivers within two (2) feet of the
sensor during calibration process could cause sensor interference,
calibration errors and affect sensor accuracy. Please refrain from using
these devices during sensor calibration.
Determine which calibration procedure you will use to calibrate the
sensor - Single Point or Zero Point calibration. For best results, the
sensor should be allowed to warm-up for at least ten minutes prior to
calibration.
Note:
The calibration kit is not necessary to perform a Single
Point Calibration.
Single Point Calibration
The reference measurement device should be warmed up in normal
measurement/operating mode. The Model 9002 should be in an
environment where concentrations will remain very stable for a
minimum of 10 minutes during calibration. Avoid breathing in the
direction of the sensor; exhaled air contains high levels of moisture and
could disrupt the calibration process.
Perform a Single Point Calibration as follows:
1. Press and hold the Clear + Enter buttons on the Model 9002 for 5
seconds. The word CAL will appear in the top line of the LCD
display.
2. Use the Arrow buttons to change the display to read SINGLE. When
SINGLE is displayed, a water vapor value will display in the lower
screen.
3. Use the Arrow button to adjust the sensor to reflect the concentration
displayed on your reference device.
4. Press the Enter button to calibrate the sensor to the value selected on
the display based on ambient air conditions. Once the Enter button
is pressed, the calibration process will take approximately 8 minutes,
during which time the green LED below the display will flash. Once
calibration is complete, the sensor will revert to its normal display
mode.
NOTICE!
Telaire Vaporstat™ Model 9002
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