ATT2100 TEMPERATURE TRANSMITTER
Operation Manual M2100-REV-G
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5.9 Calibration
Scaled system implement by calibrating the transmitter. Trim function have several function for the
calibration. Smart transmitters operate differently than analog transmitter. A Smart transmitter uses a
microprocessor that contains information about the sensor's specific characteristics in response to
pressure and temperature inputs for calculating Process Variable. The trim and rerange functions also
differ. Reranging sets the transmitter analog output to the selected upper and lower range points and
can be done with or without an applied pressure. Reranging does not change the factory
characterization curve stored in the microprocessor. Sensor trimming requires an accurate pressure
input and adds additional compensation that adjusts the position of the factory characterization curve
to optimize transmitter performance over a specific pressure range. Rerange functions provides ability
to readjust the 4~20mA points sensor inputs.
5.9.1 Sensor Trim
The Sensor Trim the transmitter sensor input signal convert A/D to lead and how it interprets the
values which it inputs with digital the contents of such interpretation and it is regarding to change is
connected actually in the sensor which in order to correspond.
There are three waysto trim the sensor : Sensor zero trim, full trim and zero adjustment.
Sensor zero trim is a one-point adjustment typically used to compensate for mounting position
effects or zero shifts caused by static pressure.
Two point trim is a full sensor tirm, in which two accurate end-point pressure are applied(equal to or
greater than the range values), and all output is linearized between them. You should always adjust
the low trim value first to establish the correct offset.
5.9.2 DA (Digital to Analog) Trim
When the D/A trim convert sensor input signal to 4~20mA output, this ouput value scale minuteness.
Cyclic you recommend to scale analog output for maintain scale.
This function can manage the error about analog conversion if digital value for loop current output.
