Vaisala HMT370EX - Environmental Compensation and Measurement Settings; Environmental Compensation and Measurement Settings Overview

9. Environmental compensation and
measurement settings
9.1 Environmental compensation and
measurement settings overview
Pressure compensation
You can configure a pressure compensation value to HMT370EX using either the local display
interface or Vaisala Insight PC software.
You must enter the pressure compensation value in order to
accurately measure calculated parameters that require pressure data. By default,
the pressure compensation value is set as 1013.25 hPa.
CAUTION!
Filtering factor
If the measuring environment produces occasional exceptionally high or low readings that
need to be averaged out in the output, you can apply a filtering factor to the measurement
output. The filtering factor defines the speed at which the latest measurement is integrated
into the transmitter's output. For example, setting the filtering factor to 0.500 means that the
displayed output is a 50%+50% combination of the previous measurement and the most
recent measurement. To show the latest measurement directly in the output, set the filtering
factor to 1.000 (no filtering).
HMT370EX has 2 alternative filtering factor options: either a default filtering factor that uses a
13 second moving average (T90), or a custom filtering factor defined by the user.
The filtering factor can be configured using the local display interface or Vaisala Insight PC
software.
Calculation coecients
When required, you can define the molar mass of the ambient gas (default value: 28.965 g/
mol) and oil-specific calculation coecients. The oil-specific calculation coecients
(selections Oil A and Oil B) are applicable only for the HMP378F oil probe model.
The molar mass of the ambient gas must be defined when
calculating gas dependent humidity parameters.
CAUTION!
HMT370EX User Guide M212305EN-B
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