4
below your desired comparison temperature, say +4°C or +7°C as
appropriate. You can use your reference thermometer for this.
(0.5 litres of water in a plastic beaker at +7°C with an ambient
temperature of 20°C exhibits a temperature rise of less than 0.1°C per
minute.)
Switch on both thermometers and insert both the probes into the water
to a depth of at least 50mm (2 inches). Hold the probes so that their tips
are very close together and use the probes to stir the water. The water
should be stirred in the centre of the beaker away from the sides. The
agitation rate should be approximately one rotation per second.
Once the KM20REF is displaying the required temperature of
comparison and this reading has been stable for 30 secs the reading of
the food thermometer can be taken and recorded.
If the reading from the food thermometer differs from the traceable
reading of the KM20REF by ±0.5°C or more, the food thermometer and
probe should be returned to the manufacturer for recalibration.
Note:
The traceable KM20REF reading is obtained by adding the
appropriate adjustment. This adjustment is obtained by taking the
applied temperature and subtracting the corresponding measured
value. See the example below:
Applied Temperature
Measured
Adjustment
–18.0°C
–18.2°C
+0.2
0.0°C
–0.1°C +0.1
+5.0°C
+5.1°C
–0.1
+8.0°C
+8.1°C
–0.1
+20.0°C
+20.2°C
–0.2
Note:
In an ideal world your tests should be conducted at exactly
the same points as those indicated in the “Measured” column of your
KM20REF Certifi cate. For all practical purposes it is acceptable to
apply the adjustment factor provided the readings are ±1.0°C of the
“Measured” value.
If then when conducting the test the following results were achieved
KM20REF reading
+8.1°C
Food thermometer reading
+8.5°C
your results sheet would be fi lled in as follows:
Summary of Contents for KM20REF
Page 1: ...KM20REF REFERENCE THERMOMETER...
Page 9: ...8...
