TEMPERATURE CALIBRATION. Refer to the Service Mode section of this manual for a detailed explanation of temperature calibration. For Health Care sterilizers use the Steam calibration method. For Scientific units use the Oil Bath calibra- tion method, where required; otherwise the Steam method may be used.
TEMPERATURE CALIBRATION. 2.4.1 A temperature bath is prepared at a specified range. Using a CTD to monitor the temperature the Xxxxxx is allowed to soak while the heater/chiller is allowed to run. The computer polls both the CTD and Xxxxxx for the values of their onboard thermometers, these values are then stored for processing. After running the desired temperature range the data is plotted and a linear relationship between the two data sets is found. The resultant gain and offset values are then used as coefficients for Xxxxxx’x temperature sensor.
TEMPERATURE CALIBRATION. The best standard for TGA temperature calibration is the use of ferromagnetic standards. These materials undergo a reversible, second-order phase transition from the ferromagnetic to the paramagnetic state when a critical temperature (Xxxxx temperature) is exceeded and loose the strong magnetization typical of ferromagnetic materials. A magnet appropriately placed above or below the furnace provides the magnetic field that attracts the reference materials placed in the sample holder. When going through the Xxxxx transition the reference material magnetization vanishes resulting in an apparent weight change. Each ferromagnetic material undergoes the ferromagnetic-paramagnetic transition at a reproducible, characteristic temperature that is only determined by the chemical composition of the ferromagnetic sample. A working group under the auspices of the International Congress for Analysis and Calorimetry (ICTAC) selected a series of alloys having Xxxxx temperatures approximately every 200 ºC between 152 and 1116 ºC and the Xxxxx temperatures of these reference materials were determined in an interlaboratory test (Xxxxxxxxx, 2003). These materials (alloys of cobalt and nickel) are available from TA Instruments. Alternatively, Xxxxx Point calibration kits spanning between 163°C (Alumel alloy) and 1000°C (Hisat-50 alloy) are available from Xxxxxx-Xxxxx.
