3. OPERATION

Ensure that the instrument is connected to a suitable supply or has charged batteries and that the required input connections are made.

Switch “on” using the rear mounted rocker switch.

The display will show “Pr 2.1” or “Pr 1.4” the programme designation. There is a short delay while internal checks are carried out, then the input A value will be displayed.

i)To read sensor temperature directly

a)PRT input A is automatically selected at switch-on. Brief repeated key presses will step through the various functions or holding the key depressed will auto repeat (scroll through); this applies to the other functions as well.

Note: If for any selected channel, the sensor is either not connected or has a faulty

connection (including sensor open-circuit), the LED display will show:- “Err 3”

Press any button to resume normal operation (either select another channel or rectify any fault and continue intended use).

b)Press CHANNEL to select inputs A,B or A-B (differential).

c)Press UNITS to display the desired units °C, °F, K, or Ω

ii)To read Differential Temperature

The difference in temperature between two PRT sensors can be obtained by displaying A-B.

Ensure that the necessary sensors are connected to both A and B inputs as required.

Press CHANNEL to select A-B

Press UNITS to display the desired units

The value now displayed is the difference between the input A and input B (A-B) for the sensor type indicated.

Null Feature

For calorimetry and other applications to optimise the precision of differential measurements, probe tolerances can be nulled by pressing the NULL key when in A-B mode. This gives an A-B reading of zero when pressed regardless of any real difference value.

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