Thermo Scientific 49iQ, Instruction Manual

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Operation
Settings
3-72 49iQ Instruction Manual Thermo Scientific
The Range Mode Selection screen is used to switch between the various
range modes: Single, Dual, and Auto Range.
Home Screen>Settings>Measurement Settings>Range Mode Selection
The Range Mode Selection screen contains the following information:
●
Single: In single range mode, there is one range, one averaging time,
and one span coefficient.
●
Dual: In the dual range mode, there are two independent analog
outputs. These are labeled simply as the “High Range” and the “Low
Range”. Each channel has its own analog output range setting,
averaging time, and span coefficient.
This enables the sample concentration reading to be sent to the analog
outputs at two different ranges. For example, the low O
3
analog output
can be set to output concentrations from 0 to 50 ppb and the high O
3
analog output set to output concentrations from 0 to 200 ppb.
In addition, each O
3
analog output has a span coefficient so that each
range can be calibrated separately. This is especially necessary if the two
ranges are not close to one another. For example, the low O
3
range is
set to 0–50 ppb and the high O
3
range is set to 0–1,000 ppb.
●
Auto: The auto range mode switches the O
3
analog outputs between
high and low range settings, depending on the concentration level. The
high and low ranges are defined in the Range Settings menu.
For example, suppose the low range is set to 500 ppb and the high
range is set to 1,000 ppb. Sample concentrations below 500 ppb are
output based on low range selection and sample concentrations above
500 ppb are output based on high range selection. When the low range
is active, the range mode selection status output is at 0 volts. When the
Range Mode Selection