More About Calibration; Adjusting Final Calibration; Zero Deadload A/D Counts; Calculating The Span Coefficient - Rice Lake IQ plus 710 Installation Manual

4.4

More About Calibration

The following topics provide additional information
about compensating for environmental factors
(Section 4.4.1) and diagnostic information for
determining expected zero and span coefficients.
4.4.1

Adjusting Final Calibration

Calibration may be affected by environmental factors
including wind, vibration, and angular loading. For
example, if the scale is calibrated with 1000 lb, a
strain test may determine that at 2000 lb the
calibration is 3 lb high. In this case, final calibration
can be adjusted by tweaking WVAL to 998.5 lb. This
Discontinued Product
adjustment provides a linear correction of 1.5 lb per
1000 lb.
To adjust the final calibration, return to the
prompt and press to show the test weight value.
Press or to adjust calibration up or down. Press
to save the value, then press
CALIBR menu.
4.4.2

Zero Deadload A/D Counts

Table 4-1 lists the ideal A/D counts that result from
input signals of 0–45 mV with zero deadload. Actual
values will typically be higher than the values shown
in Table 4-1.
Input Signal (mV)
0
1
2
3
4
5
6
7
8
9
10
15
20
30
45
Table 4-1. Ideal A/D Raw Counts
40 IQ plus 710 Installation Manual
WVAL
to return to the
Raw A/D Count
105 000
126 000
147 000
168 000
189 000
210 000
231 000
252 000
273 000
294 000
315 000
420 000
525 000
735 000
1 050 000
4.4.3

Calculating the Span Coefficient

The span coefficient value displayed by the WSPAN
parameter can be calculated using the following
formula:
(21000 * mV_signal_input) + zero_coefficient
where
mV_signal_input
input when the test weight is applied and the
is the WZERO value. Actual values
zero_coefficient
typically vary from the calculated value.
is the change in the signal