Optical Scientific Inc
OFS 2000CW User’s Guide
P/N 1910-905
Rev. 03/28/13
39
Current Loop
(continued)
Current Loop 1 - Velocity
sets the velocity
measurement range. Default velocity range is 0
to 40 m/s (meters per second). The user can
opt for a
lesser range by entering “1” and
following the prompt. Note: The measurement
accuracy is equal whether full-range or
reduced range.
Current Loop 2 - Volume
is the volumetric
flow output range, and is not a setup variable. It
is displayed to show the range and confirm the
UOM.
Current Loop 3 - Temperature
is available as
a factory-purchased option. It is not a setup
variable. It is displayed to show the range and
confirm the UOM.
Current Loop 4 - Pressure
and is available as a factory-purchased option. It is not a setup variable. It is
displayed to show the range and confirm the UOM.
4.2.5 Correction Factor
In some cases there will be a consistent
difference (high or low offset) between the
values reported by the OFS unit and other data
references - either calculated or determined by
R
elative
A
ccuracy
T
est
A
udit
(RATA)
procedure. In such a case, the OFS baseline
can be offset to match the user's equipment.
To determine offset required: Divide the
reported/calculated flow number by the OFS
flow number. For example:
Reported/calculated flow = 20 m/s
OFS reported flow = 18.5 m/s
20/18.5 = 1.082
1.08 = 8% so +8 should be typed in.
The plus (+) and minus (-) signs are required.
To clear any previous entries type in “+0” (“plus zero”)
Enter an “S” command to see that the correction factor has been set.
From an instrumentation perspective, this is a single point span adjustment.
2
(To check your figure simply multiply ex: 1.08 X 18.5 = 19.98)
Figure 4.7 Current Loop Assignments
Figure 4.8 Correction Factor Entry
