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sensing.honeywell.com
Limitless™ Point-to-Point Wireless Pressure Sensor
PRESSURE SENSOR GLOSSARY OF TERMS
Absolute Pressure (a) – Pressure measured relative to a perfect
vacuum (zero pressure) reference.
Absolute Pressure Sensor – Product whose output is proportion-
al to the difference between applied pressure and a built-in fixed ref-
erence to vacuum (zero pressure). Typically the Minimum Operating
Pressure (Pmin.) is set to absolute zero pressure (perfect vacuum).
Accuracy – The maximum deviation in output from a Best Fit
Straight Line (BFSL) fitted to output measured over the Compen-
sated Pressure Range at Reference Temperature. Includes all errors
due to: Pressure Non-Linearity, Pressure Hysteresis and Non-Re-
peatability.
Best Fit Straight Line (BFSL) – The straight line fitted through a
set of points which minimizes the sum of the square of the devia-
tions of each of the points from the straight line (‘least-squares’
method). See also Pressure Non-Linearity.
Burst Pressure – The maximum pressure that may be applied to
any port of the product without causing escape of pressure media.
The product should not be expected to function after exposure to
any pressure beyond the burst pressure. See also Overpressure.
Full Scale Span (FSS) – The algebraic difference between output
signal measured at the upper and lower limits of the Operating Pres-
sure Range. Also known as ‘Span’ or ambiguously as ‘Full Scale
Output’. (See Figure 2.)
Figure 2. Illustration of Key Pressure Sensor Terms Relative to
Operating Pressure Range
Full Scale Span
Operating Pressure Range
Max. Operating
Pressure (Pmax.)
Min. Operating
Pressure (Pmin.)
Reference
Pressure
Pressure
Sensor
Output
Offset
Gage Pressure (g) – Pressure measured relative to the local ambi-
ent (atmospheric/barometric) pressure. Also known as ‘Gauge’.
Gage Pressure Sensor – Product whose output is proportional to
difference between applied pressure and local ambient (atmospher-
ic) pressure. Typically the Minimum Operating Pressure (Pmin.) is set
to atmospheric pressure.
Maximum Operating Pressure (Pmax.) – The upper limit of the
Operating Pressure Range. (See Figure 1.)
Minimum Operating Pressure (Pmin.) – The lower limit of the
Operating Pressure Range. (See Figure 1.)
Offset – The output signal obtained when the Reference Pressure is
applied to all available pressure ports. Also known as ‘null’ or ‘zero’.
(See Figure 1.)
Offset Error – The maximum deviation in measured Offset at Refer-
ence Temperature relative to the ideal (or target) Offset as deter-
mined from the Ideal Transfer Function. See also Thermal Effect on
Offset.
Operating Pressure Range – The pressure range (or ranges) over
which the product will produce an output proportional to pressure
within the specified performance limits. (See Figure 1.)
Operating Temperature Range – The temperature range over
which the product will produce an output proportional to pressure
but may not remain within the specified performance limits.
Output Resolution – The smallest difference between output signal
readings which can be meaningfully distinguished or resolved.
Overpressure – The Absolute Maximum Rating for pressure which
may safely be applied to the product for it to remain in specifica-
tion once pressure is returned to the Operating Pressure Range.
Exposure to higher pressures may cause permanent damage to
the product. Unless otherwise specified, this applies to all available
pressure ports at any temperature within the Operating Temperature
Range. Also known as ‘Proof Pressure’.
Pressure Hysteresis – The maximum difference between output
readings when the same pressure is applied consecutively, under
the same operating conditions, with pressure approaching from op-
posite directions within the specified Operating Pressure Range.
Pressure Non-Linearity – The maximum deviation of product
output from a straight line fitted to the output measured over the
specified Operating Pressure Range. Standard methods of straight
line fit specified for this calculation are either BFSL or TSL.
Span Error – The maximum deviation in measured Full Scale Span
at Reference Temperature relative to the ideal (or target) Full Scale
Span as determined from the Ideal Transfer Function. See also
Thermal Effect on Span.
Thermal Effect on Offset – The maximum deviation in Offset due
to changes in temperature over the Compensated Temperature
Range, relative to Offset measured at Reference Temperature.
Thermal Effect on Span – The maximum deviation in Full Scale
Span due to changes in temperature over the Compensated Tem-
perature Range, relative to Full Scale Span measured at Reference
Temperature.