Ashcroft ATE-2 - Handheld Calibrator - Manual (Page 43)

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Press left and RIGHT ARROWs to position cursor beneath
desired numeric character
Press UP and DOWN ARROWs to scroll numeric values.
When desired numeric value is displayed in proper decimal
position
Press left or RIGHT ARROW to move cursor beneath the next
digit to be programmed
When desired Full scale value is displayed on screen for example
00006.00000
Press ENTER to accept
HHC will go back to Percent Error MENU and advance to the next
programmable parameter.
Use DOWN or UP ARROW to highlight “Enter % Error Mode”
Press ENTER
The HHC is now actively measuring the Percent Error of the
device under test.
The HHC is equipped with firmware that can add or subtract the
measured pressure values from two installed Quick-Select pres-
sure modules. This allows for measurement of what are com-
monly referred to as “high-line” or elevated static differential pres-
sures. The ability to add the measured values of the two installed
Quick-Select pressure modules allows for the addition of a mea-
sured barometric pressure from an absolute pressure module to
the measured pressure from a gauge or differential pressure. This
capability can use gauge measurement Quick-Select pressure
modules for absolute pressure measurement.
Accuracy of Dual Module Measurements
The accuracy of measurements made using the difference or
sum of two modules is a function of the full scale range of the
Quick-Select pressure modules used and, in the case of differ-
ential pressure measurements, the magnitude of the differential
pressure range.
For dual sensor summation measurements:
The worst case inaccuracy would be the sum of the inaccuracies
of the two Quick-Select modules used for the measurement. For
example, if the measurement is made with two +0.1% full scale
modules the maximum inaccuracy would be +0.2%. In actual
use, it is generally acceptable to use the Root Sum of the Square
(RSS) method of determining the accuracy of a multiple compo-
nent measurement system. Using the RSS method the accuracy
of the dual module summation is approximately +0.14% of span.
SECTION 15 h. PERCENT (%) ERROR FUNCTION
CONT.
SECTION 15 i. DUAL MODE FUNCTION
Output FS
00006.00000
^
Enter to accept
Esc to cancel
50.000
In(PSi) Out(volts)
% error
2.423
0.38