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Tubes, Test
Test Tubes with Rims
Borosilicate glass tubes have fire-polished rims and optimal wall thickness for maximum
TUBES, TEST continued on next page.
heat and chemical resistance.
o.d. x Length
(mm)
Make Melting Point Determinations Using a
Thiele-Dennis Tube
Catalog No.
A small quantity of the substance in question is placed into a small capillary tube. The capillary tube (with the unknown
inside) is then attached to a thermometer. A rubber band will do it.
Fill the Thiele-Dennis tube (or an Erlenmeyer flask) with water if the melting point of the solid is less than 100 °C or oil if
the melting point is greater than 100 °C (silicon oil is best, but corn oil will do). Remember that heated oils may both expand
and also smoke slightly at elevated temperatures. The rubber band may come loose if subjected to hot oil. Immerse the
thermometer (with the capillary tube attached) so that the rubber band is kept out of the oil.
Heat the Thiele-Dennis tube (see drawing) at a temperature rise of about 10 °C per minute to get a rough melting point.
Then repeat the procedure, heating the tube at a much slower rate (about 1 °C per minute) to get an accurate melting point.
A pure substance will begin to melt abruptly, and the melting will be complete within a 1–2 °C temperature range. The unique
configuration of the Thiele-Dennis tube is designed to create continuous oil flow when heated so no stirring or shaking
is
required. Convection currents created by the heat do the stirring for you.
Test Tubes without Rims
GP6060, etc.
Cork or stopper
notched to permit
escape of air
Level of heating
fluid at 200°
Level of heating
fluid at room
temperature
Capillary tube
containing solid
Thermometer
Rubber band or
segment of
rubber tubing
Heating
fluid
Laboratory
Burner
Thiele-Dennis Tube or
Erlenmeyer Flask
Test Tubes without Rims
Rimless, borosilicate glass tubes for convenience in plugging and rack storage. Ends
are fire polished. Commonly referred to as culture tubes.
Catalog No.
o.d. x Length
(mm)
Capacity
(mL) Price/Each Price/Pkg. Price/Case
GP6060 6 x 50 0.5 $ .46 $ 31.68/72 $302.40/720
GP6061 10 x 75 3.0 .48 33.12/72 316.80/720
GP6062 12 x 751 5.0 .48 33.12/72 316.80/720
GP6063 13 x 1002 9.0 .51 35.28/72 338.40/720
GP6064 16 x 100 11.0 .59 40.32/72 305.28/576
GP6065 16 x 125 15.0 .64 43.92/72 334.08/576
GP6066 16 x 150 20.0 .75 51.84/72 397.44/576
GP6067 18 x 150 27.0 .81 54.00/72 397.44/576
GP6068 20 x 150 34.0 .92 61.92/72 460.80/576
GP6069 25 x 150 55.0 1.60 111.60/72 432.00/288
1Known as Kahn Tube
2Known as Wasserman Tube
Capacity
(mL) Price/Each Price/Pkg. Price/Case
GP6005 12 x 75 5 $ .51 $24.00/50 $ 90.00/200
GP6010 13 x 100 9 .51 24.50/50 94.00/200
GP6015 15 x 125 14 .72 34.00/50 128.00/200
GP6020 16 x 150 20 .77 36.50/50 138.00/200
GP6025 18 x 150 27 .75 35.50/50 132.00/200
GP6030 20 x 150 34 .96 46.50/50 180.00/200
GP6035 25 x 150 55 1.60 77.00/50 296.00/200
GP6040 25 x 200 70 1.95 94.50/50 366.00/200
Test Tubes with Rims
GP6005, etc.
Test Tubes without Rims, Disposable
Rimless tubes exactly the same as those tubes listed on page 280 except these
have a lighter wall thickness and are considered disposable in industry. However,
these tubes will hold up to repeated use. Commonly referred to as culture tubes. Not
intended for high heat.
Catalog No. Description Size (mm) Pkg. Size Price/Pkg.
GP9165 Test Tubes without
Rims, Disposable
6 x 50 300 $ 23.05
GP7034 10 x 75 250 18.10
GP7035 12 x 75 250 18.15
GP7036 13 x 100 250 22.20
GP7037 16 x 100 250 27.80
GP7038 16 x 125 250 32.25
GP7039 16 x 150 250 35.00
GP9263 18 x 150 125 24.30
GP7041 20 x 150 250 77.65
GP9164 25 x 150 250 128.00
Test Tubes without Rims, Disposable
GP9165, etc.
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