Factory calibrated and completely sample independent, Model 1021 works with Model 2100 conductivity meter and can measure conductivity from 2.5 micro-Siemens/cm (10-6) to 25 femto-Siemens/cm (10-15). Unit can be disassembled and reassembled for cleaning in seconds without any change in calibration or cell constant, and portable design allows use on bench tops or in laboratory fume hood. Applications include monitoring liquid systems where conductivity is measured in flowing environment.