Chapter 4: Changing The Gain And Offset Ranges - Mantracourt ALA5 User Manual

3. Gently ease the base out of the cover
ensuring that the cable slides through
the loosened gland to avoid any strain on
the internal connections.
Calibration:
1. Apply the low calibration conditions (weight, force or mV/V). Set the output to 4mA using the Zero
potentiometer.
2. Apply the known high calibration conditions (ideally between 75% and full scale) and adjust the Span
potentiometer to give the required output current for the known input.
i.e. 16mA for 4-20mA final calibration with 75% input or 20mA if 100% input.
When re-assembling the ALA5 it is imperative that the 'O' is fitted correctly and the cable gland re-tightened to
maintain a gas-tight seal.

Chapter 4: Changing the Gain and Offset Ranges

The ICA5ATEX amplifier is supplied un-calibrated but optimized for a sensitivity of 2.5mV/V with a 1k bridge.
To accommodate other sensitivities the gain resistor, 'R2' (see below) can be changed to a value derived from the
following formula.
Figure 4.1
N.B. a high quality resistor (e.g. 1% 25-50 ppm metal film) should be used for best performance. It may be necessary
to use an E96 value for optimum trim range: -
Mantracourt Electronics Limited ALA5, ILEAtex and ICA5Atex User Manual
4. The ICA5ATEX amplifier will now be
exposed allowing access to the two
trimming potentiometers.
6