1. Appearance and routine inspection
(1) The flash point tester should have the instrument name, model, manufacturer name, serial number and other signs.
(2) The appearance of the instrument should not have mechanical damage that affects the normal operation of the instrument. All function keys should be intact, work normally, and the digital display should be complete; the supporting auxiliary equipment should be intact and have no effect on the test results.
2. Preparation before calibration
According to different types of flash point testers, debug the indicators of the instrument according to the methods specified in the corresponding instrument instructions to make them meet the relevant requirements of the instructions.
3. Instrument repeatability calibration
According to the measurement range of the instrument, select one or two standard materials with different flash point values within the validity period (ie open or closed flash point standard materials), and repeat the measurement twice to obtain the flash point measurement values T1 and T2. The result vT calculated by the following formula is the repeatability of the instrument.
$T=rT1-T2r;
In the formula: T1, T2 - the measured value of flash point; $T - the repeatability of the instrument.
4. Calibration of the indication error of the instrument
The operation is the same as above, respectively take the average value T of the two measured flash point measured values T1 and T2, and then correct the average value T to the average value Tc of the flash point values under standard atmospheric pressure (10113kPa), and calculate Tc and the standard value of the standard material. The difference of Ts is used as the indication error of the instrument.
Tc=T+0125(10113-p);
In the formula: T-the average value of the flash point measurements under ambient atmospheric pressure; p-ambient atmospheric pressure.
kPavTc=Tc-Ts;
In the formula: vTc - the indication error of the instrument; Ts - the standard value of the standard material; Tc - the average value of the corrected flash point measurement value.
The value of the indication error value should be compared with the relevant indicators in the corresponding national standard used.