High Process Consistency

Typically, analytical sensors output a weak, analog signal. Interference of the signal caused by nearby electromagnetic fields (e.g., from motors) and humidity in the environment can alter the signal or cause it to fluctuate. Also, transmitting the signal over long cables can lead to it being degraded and unreliable. Analytical sensors that output a digital signal are not affected by electromagnetic fields, moisture, or cable length.

Extremes of pressure, temperature, pH as well as conditions such a high percentage of solids in the medium can impact analytical sensors, leading to the need for frequent maintenance to restore measurement accuracy and also reduced sensor life. 

For analog pH sensors it can be problematic to tell if a sensor is working correctly. However, there are various indications that a pH sensor is not operating as it should, e.g., slow response time, high membrane resistance, small slope, and large offset. ISM pH sensors continuously monitor their condition and predict how many days remain until maintenance, to restore correct operation, will be due. If maintenance is not required, you can be confident that an ISM sensor is working reliably.