Cole-Parmer Liquid-In-Glass Thermometer Separation What You Need To Know

Liquid-In-Glass Thermometer Separation –
What You Need To Know

All Liquid-In-Glass Thermometers may be subject to separation; a disruption of
the liquid column such that small amounts of liquid are not united with the rest
of the liquid in the thermometer. Separation can occur for many reasons including
improper handling and storage. To help prevent separation when not in use,
thermometers should be stored at an angle of at least 15 degrees, preferably
in a vertical position.

Even when stored and used properly, a Liquid-in-Glass Thermometer may separate.
This does not mean that the thermometer is defective. Instead, there are a few
methods that can be used to reunite the liquid in the column.

Cooling Method A:

• Place a mixture of dry ice and alcohol in a beaker

• Place the bulb of the thermometer only into the beaker

• Hold until all liquid retreats into the bulb

Heating Method B:

• Place water in a beaker

• Heat to a gentle boil

• Place the bulb of the thermometer only into the beaker

• Hold until all liquid collects at the top of the thermometer

Cooling Method A

Thermometer Rack
Catalog No. EW-93860-00

Expansion Chamber

Heating Method C:

• Use extreme caution

Heating Method B

• Light Bunsen burner to create a soft yellow ame.

If you see a blue ame lower the gas input

• Carefully move bulb of the thermometer into and out of

the ame. Do not hold in the ame for any period of time

• The liquid will expand into the expansion chamber.

Be sure not to ll the expansion chamber more than ¾ full

The key to successful reunication is to determine which method is
best for the thermometer you own. Below is a useful reference guide:

Reunification Matrix

Temperature Range

If Thermometer Has/Is

Expansion Chamber Contraction Chamber PFA Coating* Longer than 14" Cooling Heating

Above -10°C (14°F) and
below 110°C (230°F)

Above -10°C (14°F) and
below 150°C (302°F)

Above -10°C (14°F) and
below 260°C (500°F)

Below -10°C (15°F)

* PFA Coated thermometers have a thin layer around the thermometer with a softer feel than non-PFA coated thermometers

X
X
X
X

X
X
X
X

X
X
X
X
X

X
X
X
X

X

X

X

X

X

X

X

X

X
X

X
X

X
X

X

X
X

Reuniting Method

Recommended

A

A

A

A

A

A

A

A

Scale

Thermometer

Separation

Immersion
Line

Contraction
Chamber

C
C
C
C

C
C
C
C

C
C
C
C
C

B
B
B
B

Non-PFA

Coated

Bulb

PFA
Coated

CO-01050-RevA

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