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Section 5
Page 65
UVTOCSetup and System Configuration.fm
Setup Menu
5.2.1.3 Range Change % Screen
Use this function only when using the autoranging function. If you are using a
fixed range, disregard this setting.
The 4–20 mA analog outputs can be used as autoranging scaled outputs.
As the TOC level increases, that increase is translated into a percentage of
the user-defined range (see
Section 5.2.1.4 ). The outputs automatically
change to the next higher range at a defined percentage setting. The other
analog output should be set to reflect the Range ID.
If the TOC level is decreasing, the range will change at 5% lower than the
defined percentage. This avoids rapid range changes when the reading is
stationary and close to the Range change %.
Changes to higher and lower ranges are discussed in detail later in
this section.
1. To enter the Range change % screen, press the UP button while in the
Inhibit level screen.
2. To modify the Range change%, press ENTER.
3. Asterisks will flash on either side of the displayed value. Use the UP and
DOWN buttons to change the value.
4. Press ENTER when the desired value is displayed. The new value is
entered into memory.
For example: If you have a 0 to 1000 mg/L analyzer, the ranges could be
divided as follows:
If range change is set at 90%, the mapped analog output changes from
Range 1 to Range 2 at 90 mg/L (90% of 100 mg/L). The change from Range 3
to Range 4 occurs at 450 mg/L (90% of 500 mg/L).
When the measurement is descending, (Range 4 to Range 3, etc.),
the range change occurs at a point 5% below the programmed value. Using
the previous example, the change from Range 4 to Range 3 occurs at
425 mg/L (85% of 500 = 425). The change from Range 3 to Range 2 occurs
at 212 mg/L (85% of 250 = 212). The change from Range 2 to Range 1 occurs
at 85 mg/L (85% of 100 = 85).
R a n g e c h a n g e %
85%
Range 1 starts at 0 mg/L and goes to 100 mg/L
Range 2 starts at 0 mg/L and goes to 250 mg/L
Range 3 starts at 0 mg/L and goes to 500 mg/L
Range 4 starts at 0 mg/L and goes to 1000 mg/L