Melting point Apparatus Manufacturer:
A melting point apparatus is a scientific instrument used to determine the melting point of a substance. Some types of melting point apparatuses include the Thiele tube, Fisher-Johns apparatus, Gallenkamp (Electronic) melting point apparatus and automatic melting point apparatus.
Melting Point Apparatus measures the melting point of a substance i.e. the temperature at which the state of the substance changes from solid to liquid. The actual melting point is an indication of the purity of a substance and hence an ideal tool for the quality control of medicines, perfumes, dyestuff and other organic crystalline substances.
Photo Electric detection.
Large Backlite LCD display.
RS-232 Interface.
Measurement of 3 samples simultaneously.
Display of initial and final melting points.
Calculation of average value of initial and final
melting points.
Platinum resistor sensor for the precise temperature
measurement.
Capillary sample tube as stipulated by
pharmacopoeia
Standard Features:
1.Advanced microcontroller based user friendly state-of-the-art product design with alphanumeric splash waterproof polyester soft keys for keyboard. User interactive software in dialog mode for ease of operation with protection against invalid entries.
2.Alphanumeric entries of Sample Name, Sample Number, Identification Number and Date for authentication. Also same on report printouts makes system foolproof and GLP complaint.
3.Non volatile memory storage of 20 programs with parameters.
4.Last run result can be viewed or printed.
5.User selectable operating modes :
Pharma mode :
Melting point is automatically detected by photo sensing and the temperature is locked & displayed as per pharmacopoeia.
Thermo mode :
Melting point is automatically detected by photo sensing and the temperature is locked & temperature is displayed by giving correction for heating rate-Thermodynamic evaluation.
6.Intelligent Lamp & Cooling fan Control for longer operating life.
7.Selectable Report Format : complying with GLP requirements.
Report giving parameter and result of last run.
Report of program parameter for 20 programs.
8.Error indication helps user to trace the problems.
9.Melting RUN can be started with last run parameters.
10.Precise temperature control for repeatable results.
11.Furnace Temperature Safety cutoffs for
No sample capillaries insertion.
No detection of melting, 15° C above the expected M. P.
No detection of melting point above 315° C
12.Specially designed Capillary Eject Mechanism for easy removal of broken capillary.
13.PC Compatibility - PC Software (optional).
The SMP10 and SMP20 have been designed with safety and ease of operation in mind making it ideal for use in education. The temperature is selected, measured and displayed digitally making it accurate and negating the need for a thermometer. The SMP10 displays temperature to 1 degree resolution while the more advanced SMP20 has a 0.1 degree resolution as well as a variable ramp rate and hold key so that the exact melt temperature can be recorded.
Two samples can be tested simultaneously. They are viewed via a magnifying lens with clear observation aided by built in illumination. Extendible back feet allow the unit to be operated at the optimum viewing angle. Full access to the block aids cleaning. The simple to follow instructions are printed directly on the instrument in most European languages for ease of use.
To operate simply select a plateau temperature via the digital display and press "start". The unit quickly heats up and remains at the selected plateau temperature until the user is ready to start the test. Insert the sample tubes and press "start". The unit then heats at a fixed rate of 2°C per minute for the SMP10 and at a user selected rate of between 1 and 10°C per minute for the SMP20. When the sample is seen to melt, note the temperature on the display. Press "stop" to end heating and cool the block.
Specifications
Measuring Range of Melting point : Ambient to 300oC
Resolution : 0.1oC
Rate of heating(oC/min) : 0.2,0.5, 1, 1.5, 2 3, 4, 5
Accuracy : +0.5oC upto200oC, +0.8 oC from 200oC to 300oC
Heating time (50 to 300oC) : 3 mins
Cooling time( 300 to 50oC) : 5 mins
Capillary sample tube size : OD 1.4mm, ID 1mm
Power Supply : 220 V +/-10%, 50Hz, 100 Watt
Dimensions : 400 x 280 x 210 mm
Weight : 12.5 kg
Melting point measurements:
Many laboratory techniques exist for the determination of melting points. A Kofler bench is a metal strip with a temperature gradient (range from room temperature to 300 °C). Any substance can be placed on a section of the strip revealing its thermal behaviour at the temperature at that point. Differential scanning calorimetry gives information on melting point together with its enthalpy of fusion.
A basic melting point apparatus for the analysis of crystalline solids consists of an oil bath with a transparent window (most basic design: a Thiele tube) and a simple magnifier. The several grains of a solid are placed in a thin glass tube and partially immersed in the oil bath. The oil bath is heated (and stirred) and with the aid of the magnifier (and external light source) melting of the individual crystals at a certain temperature can be observed. In large/small devices, the sample is placed in a heating block, and optical detection is automated.
The measurement can also be made continuously with an operating process. For instance, oil refineries measure the freeze point of diesel fuel online, meaning that the sample is taken from the process and measured automatically. This allows for more frequent measurements as the sample does not have to be manually collected and taken to a remote laboratory.
What is Melting Point?
The melting point of a solid is the temperature at which it changes from solid state to liquid state. At the melting point the solid and liquid phase exists in equilibrium (balance). The melting point of a substance depends (usually slightly) on pressure and is usually specified at standard atmospheric pressure. When considered as the temperature of the reverse change from liquid to solid, it is refereed to as the “Freezing point or crystallization point”. Due to the ability of some of the substances to super cool, the freezing point is not considered as the characteristic property of a substance. Super cooling a liquid is the process of cooling a liquid past its freezing point without it turning into a solid. When the “characteristic freezing point” of a substance is determined, the actual methodology is almost always “the principle of observing the disappearance rather than the formation of ice”, that is the “Melting Point”.
How to measure the Melting point?
Many laboratory methods exist for the determination of melting points.
Kofler bench: A Kofler bench or Kofler hot-stage microscope is a metal strip with a temperature gradient (range room temperature to 300 degree centigrade). Any substance can be placed on a section of the strip revealing its thermal behavior at the temperature at that point.
Thiele tube: Thiele tube is a laboratory glass ware designed to contain and heat an oil bath. A basic melting point apparatus for the analysis of crystalline solids consist of an oil bath with a transparent window and a simple magnifier. An oil bath is a laboratory heating device which uses boiling oil as the temperature regulator. The several grains of a solid are placed in a thin glass tube and partially immersed in the oil bath. The oil bathe is heated (and stirred) and with the help of the magnifier (and extent light source) melting of the individual crystals at a certain temperature can be observed. In large/small devices, the sample is placed in a heating block, and optical detection is automated.
How is Melting point discussed in terms of Thermodynamics?
From thermodynamics point of view, at the melting point the change in Gibbs free energy of the material is zero, but the enthalpy (H) and the entropy (S) of the material are increasing. Gibbs free energy also known as free enthalpy is a thermodynamic potential that measures the useful work obtainable from a thermodynamic system. Enthalpy is a measure of total energy of a thermodynamic system. Entropy is the measure of disorder of a thermodynamic system. Melting phenomenon happens when the Gibb’s free energy of the liquid becomes lower than the solid for that material. At various pressures, this happens at a specific temperature.
