IBP HDM97BQ - Measurement Channels and Procedures; Conductivity and Temperature Measurement

17 Adjustment and Calibration
Measuring
By pressing the key the user can select between all available channels of the HDM97Pocket .
These channels are
• Conductivity and temperature Display "CD/TEMP" only Version BN, BO, BP, BQ
• Temperature Display "TEMP" only Version BN, BO, BP, BQ if enabled
• Pressure Display "PRES" only Version BH, BM, BO, BP, BQ
• pH Display "PH" only HDM97BP, if enabled
• Flow Display "FLOW" only HDM97BQ, if enabled
• Timer Display "Time" if enabled
Conductivity and temperature measurement
In this mode the display shows "CD/TEMP" in the upper line, the temperature value in the middle line and
the conductivity value in the bottom line.
→ CD/TEMP (available in versions BN, BO, BP and BQ)
→ selection of conductivity temperature coefficient
→ reading min. value → reading max. value
Returns automatically back to measuring mode after 5 sec.
→ reset of both the min. and max. value
→ return to measuring mode
→ no function
Fundamentals of temperature compensation
Definition
Electrical Conductivity
Electrical conductivity or specific conductivity is a measure of a solution's ability to conduct an electric
current. Electrical conductivity of electrolytic solutions is strongly dependent on temperature. In order to
compare electrical conductivity measurements at different temperatures, they are standardized to a common
reference temperature. This common temperature is 25°C. The dimension unit commonly used is "mS/cm at
25°C"
Common temperature
The common temperature is the temperature at which non compensated conductivity measures and
compensated conductivity measures have the same value.
Temperature coefficient
The temperature coefficient is the relative change of the solution's conductivity depending on it's temperature
standardized to a common reference temperature. The dimension unit of this value is measured in %/K.