SOP for Melting point Apparatus.

This Document describes (Standard Operating procedure) SOP for Operation and calibration of Melting point Apparatus.

SOP for Operation and calibration of Melting point Apparatus.

I. Purpose & Scope:

  • The Purpose of this SOP is to lay down the procedure operation, cleaning and calibration of  Melting point Apparatus.
  • This procedure is applicable for operation, cleaning and calibration of melting point apparatus used in Quality Control Department

II. Responsibilities:

  • All Quality control personnel’s shall be responsible to follow and implement this SOP.

III : Introduction and Procedural Part :

General Cleaning: 

  • Ensure that the power supply to the Melting point Apparatus is switched OFF before Cleaning.
  • Clean the instrument with a clean dry cloth every day.
  • Occasionally wet cloth dipped in dilute soap solution may be used.
  • Precaution has to be taken to clean the instrument immediately wet cloth removes the moisture.

Basic Operation: 

  • Ensure that the instrument is properly connected to the power supply.
  • Switch “ON” the instrument.
  • Finely powder the sample in a mortar, if the material is crystalline and fill the capillary.
  • Start menu to Start Test.
  • Press Menu & select Scroll to Products setting and then ENTER
  • Display appears Product setting – Select Mode then ENTER
  • Display appears Melting Point.
  • As per requirements fill the details as Sample ID & set Temperature then Back to Start Menu.
  • Press menu & select Test by arrow key then press ENTER.
  • Select Sample Test by arrow key then press ENTER.
  • Select melting point then select sample test by arrow key then press ENTER.
  • Display appears Select Operator Name then Press ENTER.
  • Display appears Approval for test then Press ENTER.
  • Test Melting point started.
  • Observe the sample for Start melting point.
  • Record the observation on analytical record.

Calibration :

  • Following Melting Point Standards are dried at appropriate condition as per given instruction below. Then use for calibration of melting point apparatus.
Sr. No. Melting point Standard Melting Range Acceptance Limit Pre Drying


1 Vanillin 81°C to 83°C Over silica gel for 16 hrs. Before using.
2 Sulfanilamide 164°C to 166°C Over silica gel for 16 hrs. Before using.
3 Caffeine 235°C to 237°C Over silica gel for 16 hrs.
  • Melting point standards should be stored in tightly packed containers.
  • Fill the capillaries for the determination of melting point as applicable.
  • Follow the procedure 5.2.1 to 5.2.16
  • Determine the   melting point of the compound.
  • Record the observations in Annexure I   then enter the calibration details on “CALIBRATION LABEL” affixed on the instrument.
  • Report any discrepancy noted at the time of calibration or operating the instrument to Quality Control Manager and notify the defect to Maintenance department/ Service Engineer to rectify the error occurred in instrument.  Affix an “Under Maintenance” label on the instrument.

Frequency of calibration : 

  • Once in three months and after each maintenance job.
  • Calibration done by external agency once in a year.
  • Handle the out of calibration results as per specified SOP.
  • Maintain the instrument usage log book as per SOP Handling of instrument usage log book and inward register.

Changing frequency of silicon oil : 

  • Silicon oil to be changed yearly or as and when required

IV: Annexure :

Annexure I : Instrument Calibration Record


Annexure –I

Instrument calibration record 

   Name of Instrument     Melting point apparatus Make  
   Instrument ID No   Model  
Date of Calibration   Calibration due date  


Sr. No. Standard Used Batch Number Valid up to


Sr. No. Standard Used Observed Melting range Acceptance criteria Complies/Does not complies
1 VANILIN 81°C to 83°C
2 SULFANILAMIDE 164°C to 166°C
3 CAFFINE 235°C to 237°C


Remark: The instrument is calibrated and Complies / does not comply with the acceptance criteria.



Calibrated By:                                      Checked By:                             Approved By:

 Date:                                                      Date:                                          Date:


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