Calculating results

TM 5-6640-213-14

(3) Calculating results. Record the ice point reading and

compare it with the previous ice point reading. If the ice point is

higher or lower than 32 degrees F, all other temperature readings of

the thermometer must be correspondingly increased or decreased; i.e.,

if the observed ice point is above 32 degrees F, the correction

factor is added to the observed reading; if the observed ice point is

below 32 degrees F, the correction factor is subtracted from the

observed reading. Example: Observed ice point 33 degrees F, add 1

degree F to all observed readings; observed ice point is 31 degrees

F, subtract 1 degree F from all observed readings.

c. Preparation of Thermometer. The thermometer is prepared for

ice point determination by one of the following methods:

(1) The thermometer is maintained at room temperature (70

degrees F) (21.1 degrees C) for at least 72 hours prior to determine

ice point.

(2) The thermometer is heated to a specified temperature

and the ice point is determined immediately after heating, or within

a stated time period. If the ice point is determined after heating,

a note indicating the temperature to which the thermometer was heated

and the observed ice point must appear in the certification sheet.

The routine laboratory thermometers must be accurate to + or - 0.6

degrees F.

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