Sutron Accububble 56-0131-50-1, Руководство по эксплуатации и техническому обслуживанию

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Temperature coefficient --
This is made up of two components, the temperature
coefficient of the offset and the temperature coefficient of the slope. These can be referred to as
thermal shifts, temperature dependence, and other names. The offset is sometimes referred to as
zero. The slope is sometimes referred to as span, sensitivity, or scale factor. The following graph
illustrates why the temperature coefficient is an important specification for remote equipment. In
an indoor environment a competitor's barometer is about a 0.5 mB instrument. Over the operating
temperature range of Sutron equipment, it degrades to a +3 mB instrument.
Example Temperature error of a Competitor's 0.5 mB "Accurate" Barometer
-4
-3
-2
-1
0
1
2
3
4
-40 -30 -20 -10 0 10 20 30 40 50 60
Temperature in degrees C
Hysteresis -
This is a measure of deviation in the output when passing through an
input point from two different directions. If a pressure transducer has zero pressure applied, then
10 PSI, then 22 PSI, then 10 PSI, the difference between the two 10 PSI readings would be a
measure of the pressure hysteresis of the transducer. Pressure transducers can also have
temperature hysteresis errors. Sometimes hysteresis is lumped in with other non-repeatability
errors.
ACCURACY -
Accuracy is a measure of how closely the sensor's output matches the
"true" value of the parameter being sensed.
PRECISION -
Precision is a measure of the repeatability of the sensor. It will most
always be better than the accuracy of the sensor.
RESOLUTION
- The resolution of a sensor is the smallest change in the input that is
reflected in the output. For digital sensors it also refers to the smallest increment of the output.
This may be greater than or less than the sensor's resolution with respect to its input. Greater
resolution does not imply greater accuracy. Resolution and Accuracy are two independent
variables. The advantage of resolution in excess of accuracy is that changes in the input
parameter can be detected and tracked.
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