The instrument is calibrated and tested before it leaves the factory. No calibration is required at field.
Calibration can be performed locally without the need for hot work permits – minimizes operational down-time.
Local display and buttons enable calibration without opening the junction box.
Calibration may be required for the following reasons:
a new instrument
after an instrument has been repaired or modified
when a specified time period has elapsed
when a specified usage (operating hours) has elapsed
before and/or after a critical measurement
after an event, for example
after an instrument has been exposed to a shock, vibration, or physical damage, which might potentially have compromised the integrity of its calibration
sudden changes in weather
whenever observations appear questionable or instrument indications do not match the output of surrogate instruments
as specified by a requirement, e.g., customer specification, instrument manufacturer recommendation.
In general use, calibration is often regarded as including the process of adjusting the output or indication on a measurement instrument to agree with value of the applied standard, within a specified accuracy.
This method is being used by field customers with low-pressure glass ampulse of known PPM, which is available along with calibration chamber. In using this method, Calibration can be done same as gas cylinder method. Take the glass ampulse of gas and fix up inside the calibration chamber near the screw for puncturing. Now switch on the instrument and connect the sensor it will display zero reading and remove the guard from sensor and put sensor inside of calibration chamber and close tight for leak proof. Puncture the glass ampulse by turning screw gas will diffuse inside chamber and instrument will read display of the same PPM of ampulse if drift then turns the Pot-4 to read as corresponding display. Calibration is over.
