A second toggle switch on the right side connects the lamp and power input to the apparatus. Both the heaters are kept 'ON' in the 'LOW' as well as 'HIGH' position of the toggle switch, thus ensuring uniform heating from both sides of the block. A built in a rotary rheostat gives accurate adjustment of the rate of increase of temperature as melting point is approached. The built in lamp provides uniform and shadow less illumination of sample tube which are viewed through the magnifying lens against either a dark or bright ground selected by rotating a knob to the rear of the apparatus. The block is heated by two elements clamped to the sides. It consists of a aluminum block which accepts three capillary tubes & a mercury thermometer. Melting Point Measuring Instrument is very useful in the determination of the melting point of any substance in small quantity up to 300 C.
#Melting point measure apparatus how to#
Then cool the plate to 20° below the crude melting point, and proceed to take a more careful melting point on a second sample of the compound.Tags: / automatic melting point apparatus / buchi melting point apparatus / calibration of melting point apparatus / digital melting point apparatus / fisher johns melting point apparatus / gallenkamp melting point apparatus / how to use melting point apparatus / LABPRO / Melting / Boiling Point Apparatus 1☌ / melting and boiling point apparatus / Melting and Boiling Point Apparatus 1☌ / melting point apparatus / melting point apparatus calibration / melting point apparatus capillary tube / melting point apparatus chemistry / melting point apparatus diagram / melting point apparatus manufacturers in india / melting point apparatus price / melting point apparatus principle / melting point apparatus procedure / melting point apparatus slideshare / melting point apparatus sop / melting point apparatus uses / melting point apparatus veego / melting point apparatus working principle / Melting Point Instrument / melting point measuring instrument / Melting Point Test Apparatus / Scifa / sop for melting point apparatus / stuart melting point apparatus / thiele tube melting point apparatus / veego melting point apparatus If you do not know the melting point of a compound, first take a crude melting point by heating rapidly.Record the temperatures at which melting begins and at which the last Observe the crystals with your eye about 6" from the lens to prevent accidentally touching the hot apparatus.When the temperature is about 15 degrees below the anticipated melting point, change the setting to that indicated on the graph below.Increase the temperature rapidly at first and then slowly as the melting point is approached in the following manner: This insures that the temperature of the hot plate, thermometer, and sample will be in thermal equilibrium. The rate of temperature increase in the vicinity of the melting point must be small, about 2 degrees C per min. When finished, turn off both the unit and the thermometer and place the used melting point tube in the used melting point capillary tube receptacle. Make sure the unit is plugged in and set to zero, then turn it on.įollow the directions given below to determine an appropriate heating rate. When the crystals are packed into the bottom of the tube, place the tube into the slot behind the eyepiece on the Mel-Temp. Tap the bottom of the capillary on a hard surface so that the crystals pack down into the bottom of the tube.Īlternatively, drop the capillary tube down a length of glass tubing to pack the crystals into the bottom of the tube.
The solid should fill the tube to a depth of 2-3 mm. Crystals will stick in the open end of the tube. Pack the capillary tube by pressing the open end gently into a sample of the compound to be analyzed. If your Mel-Temp has a traditional mercury thermometer, be careful not to break it! Technique for Taking a Melting Point Note that you have to turn on both the heating block (green switch) and the thermometer (small switch on top) if your Mel-Temp has a digital thermometer. This type of melting point apparatus uses long, thin melting-point capillaries. The picture below shows a Mel-Temp melting point apparatus.
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