Printed in U.S.A. 1/19
FR# 443559-00 Rev. 7
©Copyright 2019 Dwyer Instruments, Inc.
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: 219/879-8000
Fax: 219/872-9057
www.dwyer-inst.com
e-mail: [email protected]
SETUP & CALIBRATION
Two multi-function buttons are provided for all calibration operations. With these you
can set the zero and span points, adjust the 4 and 20 mA calibration points, or reset
the 4 and 20 mA calibration points to the factory settings. All settings are stored in
nonvolatile memory so they will not be lost if the power is removed.
Zero and Span Calibration
The zero and span calibration is done with the CRF2 installed in the measured tank
or vessel. Calibrating zero or span can be done in either order as these settings are
independent of one another. The calibration can be done such that the output can go
from 4 to 20 mA or from 20 to 4 mA depending on the desired measurement for full
and empty conditions.
The span or zero calibration is activated by pressing and holding the corresponding
˝Zero˝ or ˝Span˝ button for three seconds. Set the tank level to one endpoint (i.e., full
or empty), then press and hold either the Zero or Span button corresponding to the
desired endpoint. Set the tank to the other endpoint then press and hold the opposite
Span or Zero button. Calibration is now complete.
NOTE:
Be careful to press the buttons only once within 3 seconds. Double clicking
the switches within 3 seconds will place the unit in current calibration mode. If this
happens press both buttons simultaneously to exit the current calibration mode. If
the calibration was accidentally changed, the factory calibration can be restored as
described later in ˝Restore Factory Calibration˝.
Current Calibration
The 4 and 20 mA points of the CRF2 have been calibrated at the factory and generally
will not need to be recalibrated, but if needed the points may be recalibrated. To do this
you will need a milliammeter connected in the current loop.
To calibrate the 4 mA calibration point, ˝double click˝ the Zero/4 mA button by pressing
it twice within 1.5 seconds. The milliammeter will indicate approximately 4.00 mA.
Adjust the 4 mA set point by pressing the Zero/4 mA button to decrease the current and
the Span/20 mA button to increase the current. When complete, press both the Zero/4
mA and Span/20 mA buttons simultaneously to exit the calibration mode.
To calibrate the 20 mA calibration point, ˝double click˝ the Span/20 mA button by
pressing it twice within 1.5 seconds. The milliammeter will indicate approximately
20.00 mA. Adjust the 20 mA set point by pressing the Zero/4 mA button to decrease
the current and the Span/20 mA button to increase the current. When complete, press
both the Zero/4 mA and Span/20 mA buttons simultaneously to exit the calibration
mode.
NOTE:
If the buttons are not pressed for approximately 4 minutes in calibrate mode,
the CRF2 will automatically revert to the normal operation mode.
Restore Factory Calibration
The factory 4 and 20 mA calibration points may be restored by pressing and holding
both the Zero/4 mA and Span/20 mA buttons simultaneously for 3 seconds. This must
be done in the normal operation mode.
MAINTENANCE & REPAIR
Other than the controls mentioned in this manual there are no user maintenance
adjustments or routine servicing required for this product. The unit is not field
repairable and should be returned to the factory if service is required. Disassembly or
modifications made by the user will void the warrantee and could impair the continued
safety of the product. If repair is required obtain a Returned Goods Authorization
(RGA) number and send the unit, freight prepaid, to the address below. Please include
a detailed description of the problem and conditions under which the problem was
encountered.
When the CLS2 with Sanitary Process Connection is to be used in a sanitary or hygenic
application, the unit must be cleaned and/or sanitized in accordance with appropriate
guidelines prior to installation. The CLS2 with Sanitary Process Connection is suitable
for “Clean In Place” methods.
Dwyer Instruments Inc.
Attn: Repair Department
102 Highway 212
Michigan City, IN 46360
POWER
SUPPLY
RECEIVER/
READOUT
–
–
+
+
ZERO/
4-MA
SPAN/
20-MA
OUTPUT
Figure 3: Electrical Wiring Diagram
This symbol indicates waste electrical products should not be disposed
of with household waste. Please recycle where facilities exist. Check with
your Local Authority or retailer for recycling advice.
