LEYRO LDT 2000, Manual

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6.5 Calibration
More advanced features are provided in Calibration window, accessible through its corres-
ponding button on the top toolbar. After entering, user can see a similar window to this in
fig 20.
In case if only one probe is attached to the thermometer, program will display a message
and present only the parameters of connected probe.
Calibration window presents following information:
• Analogue circuit number – serial number of thermometer’s measurement board;
• Standard resistor value (in Ohms) – to use during a resistance calibration;
• Probes – displays the serial number, last calibration date, resistance at 0°C, calibration
and correction coefficients, the temperature range and overflow flags. Below
each column is described:
• S/N - probe’s name or serial number (10 characters)
• Last calibr. - indicates last calibration date for probe. This field is filled automaticcaly
during calibration.
• R0 - probe’s resistance at 0 °C,
• Coeffs. <A, B, C> - coefficients for Callendar– Van Dusen equation for calculating resis
tance of Pt100 sensor,
• NInt – empty field left for compatibility with older firmware versions
• NCOR <a0, a1, a2> - (Negative CORrection) – coefficients of 2nd grade polynomial used
for correction of negative temperature measurements.
The polynomial can be used to fit thermometer’s reading to the value required by
the user in following maneer:
RAC= a2*(RBC^2)+a1*RBC+a0, where:
RAC =reading after correction
RBC =reading before correction
• PCOR <a0, a1, a2> - (Positive CORrection) – coefficients of 2nd grade polynomial used
for correction of positive temperature measurements.
The polynomial can be used to fit thermometer’s reading to the value required by
the user in following maneer:
RAC= a2*(RBC^2)+a1*RBC+a0, where:
RAC =reading after correction
RBC =reading before correction
• TMIN - minimum working temperature for probe,