Instruction manual

12
4.4. Conductivity Calibration
Ideally, you should select a conductivity standard with a value near the sample value you are
measuring. The next best method is to choose a calibration solution value that is
approximately 2/3 the full-scale value of the measurement range. For example, in the 0 to
1999 µS range, use a 1413 µS solution for calibration. See “Specifications”, page 22.
Preparing the Meter for Conductivity Calibration
You can calibrate at one point per range of the meter (a total of up to four calibration points).
However, only the ranges that have been calibrated have maximum ±1% full-scale
conductivity accuracy. If a range was not calibrated, the meter automatically detects the
closest range calibrated and uses that calibration information.
To maintain ±1% F.S. accuracy, you need to calibrate your meter at least once a week
if:
x You take measurements at extreme temperatures.
x You are measuring in conductivity ranges lower than 100 µS.
To maintain ±1% F.S. accuracy, you need to calibrate your meter at least once a month
if:
x You are measuring in mid-range solutions, and you wash the cell in deionized
water between usages.
The conductivity of solution varies greatly with temperature. The Automatic Temperature
Compensation (ATC) feature adjusts the fluctuations of conductivity readings in varying
temperatures to a standard temperature. These conductivity meters feature a temperature
coefficient of 2.00% per °C and normalize the readings at 25°C.