BUCHI Melting Point M-560 - Manual (Page 32)

6 Operation
32 Melting Point M-560 Operation Manual, Version D
6.4 Calibration
NOTE
BUCHI recommends calibrating each new instrument after installation. Furthermore it is recom-
mended that the instrument be recalibrated every year.
6.4.1 Calibration principle
NOTE
The instrument is calibrated using melting point standards. The calibration is valid for boiling points
as well.
Use the calibration set (11055018). This calibration set contains the melting point standards listed
below. Each standard is shipped with a certificate of analysis and an MSDS (material safety data
sheet).
The calibration set contains the following substances:
• 4-Nitrotoluene:
approx. 52 °C
• Diphenyl acetic acid: approx. 148 °C
• Caffeine: approx. 237 °C
• Potassium nitrate: approx. 335 °C
From each substance, a minimum of 6 determinations have to fulfill a standard deviation of less than
+/- 0.2 °C, otherwise the instrument will not move on to the next substance. The maximum number of
samples for each substance to reach the deviation of +/- 0.2 °C is limited to 12 samples. The instru-
ment automatically chooses the best 6 results from the determinations performed.
After a successful calibration is performed, it can be checked using the verification set (11055019).
Each standard of the set contains a certificate of analysis and the MSDS.
The verification set contains the following substances:
• Benzil:
approx. 94 °C
• p-Anisic acid: approx. 182 °C
• Phenolphthalein: approx. 261 °C
6.4.2 Calibration procedure
To start calibration, turn the rotary knob to Calibration. Press START and follow the instruction on
display.