Somat eDAQlite, Руководство пользователя

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Somat eDAQ
lite
116 I2773-4.
4
en
To accurately measure the leadwire resistance, use the four-wire resistance
measurement method. Nominal resistance values for transducer cable wires can help
to estimate the leadwire resistance (see
“Cable Resistances” on page 223 ). However,
since contact resistances at mechanical connections are difficult to estimate, measure
the leadwire resistance for optimum accuracy.
Alternatively, TCE can back calculate the leadwire resistance if the bridge resistances
are equal and known and if the resistances of the three relevant leadwires are equal.
To use this method, the bridge type and bridge resistance fields must be correct.
Ensure the transducer is stable and then click the back calculate resistance option.
Back Calculate Resistance
Select the back calculate resistance option to experimentally measure the leadwire
resistance. Note that the measurements are only valid when the bridge resistances
are equal and all leadwire resistances are equal. If the resulting values show
significant difference between the upscale and downscale resistance values, the three
relevant leadwires are not equal and the back calculate method is invalid.
Resistor to Shunt Across
Select either the upscale (-Sig to -Ex) shunt option or the downscale (-Sig to +Ex)
shunt option. Note that the downscale shunt option results in a negative span signal
value.
6.3.2 Simultaneous High Level
Add a simultaneous high level input to any ELHLS connector. For more information on
the ELHLS layer, see
“ELHLS (High Level Analog Layer)” on page 95 .
NOTE
Each channel on the ELHLS layer can have an independent sample rate and digital
filter selection.
Output Data Type
The fundamental data type for ELHLS channels is 16-bit signed, which consumes the
least amount of data storage while maintaining full 16-bit data resolution. The 32-bit
float data type adds a great deal of computational overhead and is not recommended
for high rate data collection. Use the 32-bit floating point option only if the input channel
is to be used in subsequent computed channels or DataModes that require the input
channels to be 32-bit floating point. The 8-bit signed data type adds some
computational overhead, but may be useful when only a rough picture of the
transducer data is required and/or data storage limitations are a major concern.
Digital Filter Type
Select the desired type of digital filtering for the channel. Digital filters ensure that
aliasing of the input signal does not occur. Always use a digital filter unless absolutely
certain of the frequency content of the input signal. The filter options are an eight-pole
Butterworth filter or a linear phase filter. For more information on digital filtering, see
“Digital Filtering” on page 213 .
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