Parr Instrument Performa Therm Liquid Calorimetric Thermometers - Manual (Page 2)

RE-JOINING LIQUID SEPARATIONS
All thermometers, including PerformaTherm ,
experience occasional separations, especially
during transit. In order to obtain true and
accurate readings, please follow the re-joining
instructions below.
Each Parr PerformaTherm
 calorimetric
thermometer has a contraction chamber
below the first line. If the separation
is between the bulb and contraction
chamber, draw the liquid into the bulb using a
mixture of dry ice and alcohol. Be careful not
to allow the liquid to be drawn down more
than 20
° per minute. When the liquid is in
the bulb, tap the thermometer gently until the
columns are joined. Allow the thermometer to
warm to room temperature naturally. DO NOT
hold the bulb in your hands as this may cause
the bulb to break. If the separation is
between the contraction chamber and the
top line of the thermometer range, draw the
liquid down into the bottom of the contraction
chamber using either a mixture of dry ice and
alcohol or chopped ice. Be careful not to
allow the liquid to be drawn down more
than 20
° per minute. Warm the bulb so the
two liquids join together.
Gentle tapping may be required to re-join.
Allow the thermometer to cool down to room
temperature naturally. If the separation is
above the scale or in the top chamber,
prepare a cup of boiling water and a cup of
warm water. Place the top of the
thermometer, including the top chamber, into
boiling water for at least two minutes until the
liquid joins together into the bottom of the
chamber. Place the thermometer into the
warm (bulb down) so the liquid in the bore
rises and joins together with the separation in
the top chamber. Gentle tapping may be
required to re-join. Maintain the thermometer
in warm water and allow to cool naturally until
it reaches room temperature.
If the liquid is allowed to retract faster than 20
°
per minute, a haze of liquid may be left on the
walls of the thermometer. If this happens,
warm the bulb and collect the liquid. Be sure
not to warm the bulb beyond the top line of the
thermometer. Allow the thermometer to cool
naturally, or continue using the thermometer
being careful not to allow the liquid to be
drawn down more than 20
° per minute.
Revision 1-03-02