Cannon Instrument miniAV-LT - Manual (Page 33)

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CANNON ® miniAV-LT Low Temperature Automatic Viscometer with VISCPRO ® Instruction & Operation Manual
Version 1.a— May, 2009; CANNON ® Instrument Company
2139 High Tech Road • State College, PA 16803 • USA
CHAPTER
3
CALIBRATING THE miniAV-LT
Calibration is essential for the proper operation of the miniAV-LT. The
miniAV-LT is calibrated before it is shipped to the customer. It should be
calibrated again after installation. Frequency of recalibration is at the
discretion of the user. There are two types of calibrations—the tempera-
ture 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 viscom-
eter tube. The temperature calibration should be performed first.
Calibrating temperature
Periodically, the temperature display of the miniAV-LT Bath Unit should
be verified using a reference thermometer for that temperature. The
miniAV-LT temperature control system permits the calibration of the bath
temperature to agree with any temperature reference standard, including
an ASTM thermometer inserted into the bath. The bath can be calibrated
by the user whenever the bath temperature is stable for any given target
temperature in degrees Celsius or Fahrenheit.
NOTE The test temperature is different from the idle temperature which is
30°C.
NOTE The calibration data is stored in the VISCOPRO II software database.
It is important to remember when moving the miniAV-LT from one PC to
another, the samples.mdb file should also be copied to the new PC to
keep from having to recalibrate the instrument. After calibrating the
temperature (or changing any configuration setting) the user should save
the instrument and tray settings-Save Instrument and Tray Settings under
the Configure menu. [This will insure that the proper settings will be
available if something happens, such as the serial port is changed.]
Calibration procedure
NOTE Depending on security level settings, it may be necessary for you to log
in as a manager to complete the calibration.
1. Set the bath to the desired calibration temperature and make certain
the reference thermometer temperature has stabilized.
The Goto Calibration Temperature button is used only when the
calibration temperature is not equal to the wash/idle temperature ( 30 °C).