Special Function Setup; Output Signal Reversal; Output Signal Offset - Teledyne 2020 Operating Instructions Manual

Thermal conductivity analyzer

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Thermal Conductivity Analyzer

6. Repeat step 5 for each of the special calibration gases, from the

To end the session, send:

to the analyzer from the computer.

4.9 Special Function Setup

CAUTION: The programming functions of the output signal

4.9.1 OFFSET OUTPUT/Reversal Output

Some applications require a reversal of the output signals in order

for the 4-20mA and 0-1 V DC output signals to correspond with the low

and high end of the concentration range. For example, if an application

involves the analysis of 85-100% oxygen in a background of argon by

measuring the thermal conductivity of the binary gas, the analyzer would

normally be set up so that the 100% oxygen (0% argon) concentration

would correspond to the zero level (4mA 0 V) of the output signal. Then,

85% oxygen (15% argon) would correspond to 20mA (1 V) in the signal

output.

It may be convenient for the user to have the outputs reversed so that

the 85-100% oxygen level outputs a 4-20mA (0-1 V) signal respectively.

This can be accomplished by reversing the data input to the custom settings.

Not all applications will require a reversing function, however, if this is

desirable. This can be programmed by allowing the user to set the analyzer

to read reversal output. Contact the factory for further information.

TAI has provided the output offset feature in the software for the

accuracy purpose. In many cases, the analyzer does not require this feature.

For exmple, if the analyzer has setup to analyze the sample gas of 40-50%

lowest to the highest concentrations. Escape when done.

st<enter>

reversal, polarity reversal and gain preset are con-

figured at the factory to the users application speci-

fication. These functions should only be repro-

grammed by trained, qualified personnel.

Teledyne Analytical Instruments

Operation 4

4-29

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