FIELD

The present disclosure is related to a method and system for managing the servicing of sensors, and more particularly, to a method and system for predicting sensor service for smart sensors.

BACKGROUND

Sensors are used to detect or measure physical or other properties. Many types of sensors may need to undergo periodic maintenance or replacement over time. Among the types of sensors that are employed for environmental or process monitoring or process control (e.g., whether “in-line” in a vessel, pipe, or natural or manmade body of water or “at line” in the form of a hand-carried instrument, or on a laboratory benchtop), pH sensors are among the most maintenance-intensive. The pH sensors may require, for example, frequent recalibration and periodic cleaning or reconditioning. It is, however, difficult to determine or anticipate with accuracy when such sensors will require maintenance or replacement.

SUMMARY

To address these and other shortcomings, a sensor service prediction system and method are provided for a sensor. The system includes a memory and one or more processors for implementing the operations of the service prediction method. In one example embodiment, the processor monitors sensor operations of the sensor, and provides a calendar age odometer which increments a calendar age of the sensor by a first time interval as the sensor operates. The calendar age represents a duration of time that the sensor has operated. The processor further determines a sensor temperature or other measurable environmental condition for each increment of the calendar age, and provides an accelerated age odometer which increments an accelerated age of the sensor by a second time interval according to the increment of the calendar age and the sensor temperature or other measurable environmental condition associated therewith. The processor also obtains a value of a sensor property, which degrades with usage of the sensor over time, at different calendar ages or accelerated ages of the sensor over time, and predicts when the sensor property of the sensor is anticipated to reach a sensor property threshold based on the values of the sensor property in relations to the accelerated age. The processor can thereafter output a status of the sensor property based on the prediction. Sensor service is to be performed when the sensor property reaches or exceeds the sensor property threshold.

The processor can further store or update sensor information over time in a sensor history log on a memory in the sensor, the sensor history log including the calendar age, the accelerated age and the sensor property.

The sensor can be a pH sensor, and the sensor property can be an electrode slope reflecting a relationship between electrochemical potential and pH for the pH sensor. Each increment of the sensor accelerated age can be determined according to the following relationship:
AAcc=A25·ek·(T−25)
where:

AAccis an increment of the accelerated age,

A25is an increment of the calendar age,

e is a base of the natural logarithm,

k is an experimentally determined constant, and

T is the temperature in ° C. of the sensor for the increment of the calendar age.

Furthermore, the prediction of when the sensor property of the sensor is anticipated to reach a sensor property threshold can be implemented using a linear extrapolation of the sensor property in relations to the accelerated age. The calendar age can be incremented by the calendar age odometer by adding the first time interval to a prior accumulation of increments of the calendar age, and the accelerated age can be incremented by the accelerated age odometer by adding the second time interval to a prior accumulation of increments of the accelerated age. The status of the sensor property can be outputted to a remote management system.

In addition, the processor can further provide a graphical user interface of a device type manager for the sensor. The sensor stores a sensor history log. The graphical user interface includes an email link. The processor can access the sensor history log from the sensor. In response to selection of the email link, the processor can automatically generate an email including an address for a predefined recipient, and can attach the accessed sensor history log to the email. The processor can transmit the generated email to the predefined recipient via a communication device.

The various operations can be performed on a single system or distributed between components of different systems, such as a host computer (e.g., a transmitter or computer) and the sensor.

