Cannon Instrument CAV-2000 - Manual (Page 35)

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CANNON ® Automatic Viscometer Models CAV-2100 and CAV-2200 with VISCPRO ® Instruction & Operation Manual
Version 2g — May, 2009; CANNON ® Instrument Company
2139 High Tech Road • State College, PA 16803 • USA
CHAPTER
3
CALIBRATING THE CAV
Calibration is essential for the proper operation of the CAV. The CAV is
calibrated before it is shipped to the customer. The CANNON
® represen-
tative who sets up the CAV will calibrate it again after installation.
Frequency of recalibration is at the discretion of the user. There are two
types of calibrations—the temperature calibration ensures that the
temperature probe readings conform to the reference thermometer, and
the standard calibration ensures that the mathematical constants used in
calculation of kinematic viscosity from sample flow times accurately
reflect the unique properties of the viscometer tube.
Calibrating temperature
Periodically, the temperature display of the CAV Bath Unit should be
verified using a reference thermometer for that temperature. The CAV
temperature control system permits the calibration of the bath tempera-
ture to agree with any temperature reference standard, including an
ASTM thermometer mounted within the bath (see page 16). The bath can
be calibrated by the user whenever the bath temperature is stable for any
given target temperature in degrees Celsius or Fahrenheit.
BIN settings
For every whole degree Celsius, a calibration “BIN” exists in nonvolatile
memory within the temperature control system. The “reference actual
temperature” is entered by the user as the actual temperature of the bath
according to the user’s temperature reference standard and is stored by
the bath in this memory and used whenever that particular target tem-
perature is entered. Fractional degrees will use the closest whole number
bin.
Calibration procedure
1. Using the REM/LOC key on the Bath Unit, place the Bath Unit in
Local mode. Make certain the reference thermometer temperature has
stabilized.
2. Press MENU and select 4) Calibrate Temperature. CAV-2200 users
should then select the left or right bath.
3. To calibrate temperature, select 1) Set Current Temperature Offset
and use the keypad controls to input the current temperature reading
to the nearest 0.01°, subject to the following:
A decimal point MAY be included as an entry. It should be preceded
by at least two numbers or a "0".