AZURA CM 2.1S Conductivity Monitor from Knauer

The AZURA conductivity monitor CM 2.1S is a high precision on-line monitor for the measurement of conductivity and pH in biochromatography applications. Contactless conductivity measurement. The pH electrode is optional.

Without conductivity flow cell. Flow cell and pH measurement kit have separately to be ordered.

Key Features

  • Contactless conductivity measurement
  • Fast response
  • High accuracy and reproducibility, low noise
  • Accurate and reliable monitoring through self-test and self-calibration
  • Short capillaries for minimizing band broadening and time delay between detectors
  • pH measurement kit is optional and has to be separately ordered



Flow cell

10 ml or 100 ml

Detector type


Measurement range

1 µS/cm–999 mS/cm

pH measurement



Maximum data rate

Approx. 5 Hz

Supported electrodes

Conductivity: automatic recognition

pH: all pH electrodes with BNC connector (compatible) and available flow cell

Measurement accuracy

Temperature sensor accuracy: ± 1.0 °C;

Conductivity accuracy: < 5 % full scale end value

pH accuracy: +/-0.5 pH in temperature range of 4-25 °C

Measurement precision

Conductvity precision measured in range 0.1-300 mS/cm: <2% of end value or ≤ 5 mS/cm of higher values

pH precision +/-0.2 pH in temperature range 4-5 °C

Analog outputs

2 channels

DAC 18 bit

Conductivity value

pH Value (only for the stand-alone device)

Digital outputs

LAN; RS-232

Technical parameters


electronic Serial No.


LCD, 2 x 8 characters


Ambient conditions

operating temperature: 4 to 35 °C, relative humidity: 45 to 85 %

Power supply

100 – 240 V, 50 – 60 Hz, max. 20 W


121 x 129 x 187 mm (W x H x D)