operation and calibration of melting point apparatus

1.0 Purpose
1.1 To describe a procedure for Operation & Calibration of melting point apparatus.

2.0 Scope
2.1 This standard operating procedure is applicable for Operation & Calibration

of melting point apparatus located in Quality Control laboratory at ABC Pvt. Ltd.

3.0 Responsibility
Officer QC/ Executive QC Preparation of SOP and follow the procedure as per SOP
Assistant Manager Reviewing and Training of SOP
Manager QC Implementation of SOP
4.0 Accountability
4.1 Manager Quality Control is accountable for implementation and compliance with SOP.

5.0 Procedure
5.1 Operation
5.1.1 Clean the instrument with clean and dry cloth. If required use the wet cloth followed dry cloth.
5.1.2 Connect the instrument with main power supply and turn on the switch.
5.1.3 Fill the capillary with small amount sample to be tested.
5.1.4 Tap capillary so that the sample collected at bottom.
5.1.5 Insert capillary with sample through small hole in Teflon cover of the beaker.
5.1.6 Capillary should rest on its platform.
5.1.7 Silicon Oil should be clear and colorless.
5.1.8 Keep the heater controlling knob at its minimum.
5.1.9 Switch on the power supply.
5.1.10 Put the mains switch turn on.
5.1.11 Press the start key & keep the booster switch on high position and heater knob at maximum position.
5.1.12 Set the stirrer knob so as to get uniform temperature of the liquid bath, in the vessel.
5.1.13 Control light intensity of the illuminator with the help of controller provided at the rear right hand side of the instrument.
5.1.14 Capillary should be clearly visible through magnifying glass otherwise adjust it by rotating Teflon cover.
5.1.15 Select the heater knob position from 0-8 position to select the desire temperature range of melting point according to need.

RANGE OF MELTING POINT	POSITION OF HEATER KNOB	POSITION OF BOOSTER HIGH/ LOW SWITCH	POSITION OF STIRRER KNOB
80^oC-90^oC	2.0	LOW	MAXIMUM
120^oC-130^oC	4.0	LOW	MAXIMUM
160^oC-170^oC	6.0	LOW	MAXIMUM
230^oC-240^oC	8.0	HIGH	MAXIMUM

5.1.16 When the temperature reaches within about 30o below the expected melting point of

the sample, switch the booster to “LOW” position & reduce the rate of heating by turning the

knob anticlockwise direction and set the position of the knob, so that heating rate is adjusted to about 1oC per minute.
5.1.17 Note the temperature when the sample melts completely.
5.1.18 Document the activity of operation of instrument in usages of logbook.

5.2 Calibration (Frequency: after 3 Months)
5.2.1 Place an accurately standardized and certified thermometer for the substance being examined.
5.2.2 The thermometer must be positioned in the bath liquid to its specified Emerson depth and

yet leave bulb about 2 cm above the bottom of the bath.
5.2.3 Fill the capillary tube with the Vanillin as a standard, previously dry over silica gel.
5.2.4 Switch on the mains and the ‘ON’ switch provided on the instrument.
5.2.5 Now follow the procedure as per 5.1.11 to 5.1.17
5.2.6 Note the melting point vanillin and record the observation in calibration record Format (Annexure I).
5.2.7 The acceptance criteria are given in Melting point apparatus calibration record Format.
5.2.8 Repeat the same steps for caffeine previously dry over silica gel.
5.2.9 Record the all observation in calibration record format (Annexure I).
5.2.10 Report any discrepancy observed during calibration of instrument to Quality Control

Manager or his designee for corrective and preventive action.
5.2.11 Quality Control Manager or his designee informs the defect to Maintenance Department

service engineer to rectify the defect. Affix ‘Under Maintenance’ label on the instrument.
5.2.12 Calibration should be required after maintenance.

6.0 Reference
In House Specification

7.0 Attachments
Annexure I : Melting Point Calibration Record Format

8.0 Distribution
Distribution of the controlled copy to concerned departments.
Additional copies may be issued for specific purpose.

9.0 Abbreviations
QA : Quality Assurance
QC : Quality Control
SOP : Standard Operating Procedure
oC : Degree Centigrade

10.0 Revision History