Pressure Calibration - ACR Electronics SmartReader Plus Reference Manual

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and humidity channels. To connect the EH-020A probe to your SmartReader Plus 4, follow

instruction notes packed with each RH probe set -- see Figure 4-2.

Remote Thermistor Temperature Probe

You can monitor temperature remotely using an ET series temperature probe with your

SmartReader Plus 4 by connecting the probe's two wires to the Temperature and Common

terminals. Make sure the External Temperature channel is activated and the proper equation

is selected.

1.6.3

Pressure Calibration

The pressure sensor, although subject to accuracy degradation when exposed to

contaminants and/or extreme environmental conditions, will drift typically less than 1%/year

(under clean conditions). You should check your SmartReader Plus 4 periodically and, if

necessary, recalibrate the pressure sensor. In the event that you wish to confirm the pressure

calibration of your SmartReader Plus 4 logger, you can perform your own calibration using the

adjustment provisions explained in TrendReader software.

The recommended method of calibration is to use a pneumatic pressure calibrator with a

preferred accuracy of at least 0.1% full scale.

Procedure

The procedure to calibrate is as follows:

Activate the pressure and temperature monitoring channels on your SmartReader Plus 4

if not already enabled.

Set the LOW, MID and HIGH calibration values to zero.

With the input port on the pressure sensor left unconnected (open to ambient), record the

pressure reading you see (it should be close to zero if you are using a gauge sensor or

close to atmospheric pressure if you are using an absolute sensor).

Subtract the pressure reading you recorded in step 3, from zero for the gauge sensor or

from calibrator reading for the absolute sensor, and enter it for the Low calibration

adjustment.

Connect the logger's pressure sensor to the calibrator, ensuring all connections are

completely airtight.

Adjust the calibrator to produce a test pressure equal to the full scale range of the logger

and record the pressure reading.

Subtract the pressure reading you recorded in step 6, from the full scale range of the

sensor (the calibrator reading should be the same), and enter it for the Mid calibration

adjustment.

Save the calibration changes to the logger.

NOTE: The value of the Ext. column is factory adjusted and should not be

changed.

SmartReader Plus Data Logger

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