Teledyne T803 CAUTION - GENERAL SAFETY HAZARD

Teledyne API T803 CO2/O2 Analyzer Operation Manual Setup Menu
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5.10.3.5. MANUAL ADJUSTMENT OF CURRENT LOOP OPTION OUTPUT SPAN AND
OFFSET
A current loop option may be purchased for the A1, A2 and A3 analog outputs of
the analyzer. This option places circuitry in series with the output of the A-to-D
converter on the motherboard that changes the normal DC voltage output to a 0-
20 milliamp signal (See Section 3.3.1.4).
 The outputs can be ordered scaled to any set of limits within that 0-20 mA
range, however most current loop applications call for either 0-20 mA or 4-20
mA range spans.
 All current loop outputs have a + 5% over range. Ranges whose lower limit is
set above 1 mA also have a 5% under range.
To switch an analog output from voltage to current loop, follow the instructions
in Section 5.10.2 (select CURR from the list of options on the “Output Range”
menu).
Adjustment of the signal zero and span levels of the current loop output is done
by raising or lowering the voltage output of the D-to-A converter circuitry on the
analyzer’s motherboard. This raises or lowers the signal level produced by the
current loop option circuitry.
The software allows this adjustment to be made in 100, 10 or 1 count increments.
Since the exact amount by which the current signal is changed per D-to-A count
varies from output-to-output and instrument–to–instrument, you will need to
measure the change in the signal levels with a separate, current meter placed in
series with the output circuit. See Figure 3-7 for pin assignments and diagram of
the analog output connector.
Figure 5-3: Setup for Checking / Calibration Current Output Signal Levels Using an Ammeter
CAUTION - GENERAL SAFETY HAZARD
Do not exceed 60 V peak voltage between current loop outputs and instrument ground.
07276B DCN6418