Heise PTE-2, Руководство по эксплуатации и обслуживанию

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37
The Percent Error Function allows the user to display the
output from a device under test in terms of percent error of
the full scale range of that device. This function applies to the
calibration of both temperature and pressure devices. Percent
error mode eliminates the need for manual calculations to
determine the level of accuracy of the device under test.
The HHC is capable of comparing two measurements in sev-
eral configurations
• Pressure or temperature input to current output device, such
as a transducer with 4-20 mA output
• Pressure or temperature input to voltage output device, such
as a transducer with 0-10 Vdc output
• Pressure to pressure device, such as a pneumatic controller
• Current input to pressure output device such as a pressure
regulator with 4-20 mA input signal
All input and output parameters can be programmed by the
operator.
Datalogging is possible while using the HHC in Percent Error
Mode. Datalogs will include only the actual values measured.
Datalogs will not include the percent error calculation as dis-
played on the HHC screen.
For example, if the HHC is being used to calibrate a 0-100 psi
transmitter with 4-20 mA output the HHC will display the follow-
ing data:
• Input pressure, as measured by Quick-Select pressure
module in selected engineering units that is being applied to
the device under test. This is the standard against which the
device under test is being compared.
• Output, from the transducer under test in output units (mil-
liamps)
• Percent error, calculated by comparing the theoretical mil-
liamp output of the device under test based on the measured
pressure reading, against the actual measured output of the
device under test. The HHC will indicate whether this error is
positive or negative as compared to the theoretical output.
If 50.00 psi is applied to a 0-100 psi pressure transducer with
a 1-5 Vdc output, the theoretical output will be 3.000v. If the
measured output from the transducer is 3.015v, the HHC will
display the following:
% Error terms
Input refers to any pressure or electrical signal input to both
the device under test and the pressure or temperature module
in the HHC.
Input Channel refers either to a pressure or temperature
module installed in the base unit (CH1 or CH2), or a voltage or
current signal connected to the common and input jacks.
Input Range refers to the numeric full scale range of the input
parameter. It is not necessary to program an engineering unit
for the input range. For example, a pressure transducer with
a measurement range of 0 to100 psi. The engineering unit is
automatically determined by the channel selected (pressure,
temperature, voltage or current).
SECTION 15 h. PERCENT (%) ERROR FUNCTION
50.000
In(PSi) Out(volts)
% error
2.423
0.38