ThermoWorks 822-950 MINI CALIBRATION BATH - Manual (Page 3)

Technical Description
The bath is used to cool or warm water, in order to provide calibration sources.
The bath is a compact, tabletop device, and can cool to approx. 36°F (20°C) less than the
ambient temperature, and heat to a temperature of approx. 130°F (56°C). The cooling system
is a non-wearing, CFC-free, Peltier device. The excess heat is discharged by a fan.
Operation
The bath is used to provide both cold and warm water as a source for comparison
calibration of thermometer probes.
In tests, using crushed ice and water, the bath was able to maintain a stable temperature of
32°F (0°C) ±0.9°F (±0.5°C) for over four hours.
Cooling
Place either cold water or a water and crushed ice mixture into the calibration cup. Place the
cup into the bath.
Connect to a power source and press the “Cold” button.
The operating indicator should glow and the bath starts cooling.
Note that the bath does not switch off and will continue to cool down to a temperature that is
approximately 36°F (20°C) below the ambient temperature. Therefore, if used in a cool place,
the water will eventually freeze.
When you wish to end cooling, press the “Off” button.
Disconnect from the power supply.
Heating
For warm water, connect the bath to a power supply and press the “Hot” button. (Reduce
heating time by filling with warm water.)
The operating indicator should glow and the bath starts heating.
The bath stops heating when the contents reach a temperature of approx. 130°F (56°C).
This prevents the bath from over-heating. A thermostat control starts the heating again if the
contents drop in temperature.
When you wish to end heating, press the “Off” button.
Disconnect from the power supply.
Calibration
Regular calibration (check) of a thermometer is essential to maintain confidence in your
readings. The Mini Temperature Calibration Bath provides a handy source of hot and cold water
to check one or more instruments against a Reference Thermometer. An annual calibration to
National Standards, by an authorized/accredited laboratory, is recommended, but you should
also check your instrument on a regular basis for obvious signs of error.
The frequency of calibration check will be dependent on how important accurate
measurement is to your business or process.
The calibration bath must be used in conjunction with a Reference Thermometer. This will have
been checked against and/or be traceable to National Standards.
The Reference Thermometer will have a Certificate of Calibration, and this can be used to
determine the actual temperature that the thermometer is reading by using a correction figure -
being the difference between the “Test Temperature” and the “Instrument Reading”.