User manual

905K Radio Telemetry Module User Manual
 ELPRO Technologies Pty Ltd 2010 Page 48
into the module.
5.3.3 Calibrating Analog Input
The 905K will be calibrated for a 4-20mA
signal in the factory. You can calibrate for a
different input signal.
1. If you are using a voltage signal, first set
the internal “jumpers” as per section 3.5.3
2. Select the “AIN Calibration” box on the
main display. The “AIN Range Selection”
box will display.
3. If you wish to calibrate to 4-20mA, 0-5V or 0-10V, simply select the range on the left side of
the box. If you want another range, enter the low
and high values and units on the right side of the
box - for example, for 1 – 5 volts, you would
enter 1, 5 and V.
If you enter a range on the right side, the left side is
ignored. When you have entered the range, select
“OK”.
4. The “Analog Calibration” display will appear. This
display allows you to enter user calibration values
into the 905K. First, you can check any existing
user calibration figures by selecting “Check
Calibration” - if there is any existing calibration
figures, these will appear.
5. To calibrate the analog input, connect the analog
signal to the 905K. Adjust the signal to the
minimum value (0%). Select “Process Low Value”
- the calibration value for this signal will
appear.
6. Now adjust the signal to the maximum value
(100%). Select “Process High Value”.
7. When you have finished this process, select
“Write Configuration” - this will write the
configuration values to the user-calibration
registers in the 905K. Select “Done” and the
analog signal is calibrated.
The accuracy of the analog signal can only be as
accurate as the calibration. For high accuracy measurement, you will need to use a high
accuracy mA or V meter to ensure that the high and low values are correct.
If you wist to return to the factory-calibration, select “4-20mA” at the AIN Range Selection