Per the Centers for Disease Control (CDC) Vaccine Storage & Handling Toolkit (January 2019) states, “Calibration testing should be done every one to two years or according to the manufacturer’s suggested timeline. TMDs can experience a “drift” over time, affecting their accuracy. This testing ensures the accuracy of the device continues to conform to nationally-accepted standards.”
The Primex OneVue temperature monitoring solution is inherently stable.
Our sensors are solid state devices and do not require validation procedures.
Our probes are Platinum Resistance Thermometers (RTDs) that do not have a shelf life. The operational use period starts when a probe is plugged into and powered from the sensor control unit.
As such, we advise customers to base probe replacement or recertification every two years from the “first use date” rather than “last testing date” per our manufacturer’s recommendations (see supporting data below).
In addition, CDC states “For measuring vaccine storage unit temperatures, CDC recommends using only calibrated temperature monitoring devices with a Certificate of Traceability and Calibration Testing (also known as Report of Calibration).”
They provide two methods to accomplish this:
Testing and Traceability performed by a ILAC MRA signatory body accredited Laboratory.
A laboratory/manufacturer that provides documentation demonstrating testing meets ISO 17025 standards.
Primex’ probe manufacturer uses method two and provides a certificate of traceability for each probe that clearly indicates this along with the following specific CDC requirements:
Date of calibration (Test Date)
Measurement results that indicate passed testing and documented uncertainty within suitable limits (recommended uncertainty is +/-1 F [+/-.5 C])
Measurement results for the device
Statement that calibration testing conforms to ISO 17025
As well as certification information, we provide the test dates and certification information for the actual calibration equipment that is used in the certification process.
Data supporting Primex' stance regarding probe storage effect on the calibration period is provided the graph below.
The graph details the amount of drift (or potential error) introduced by the probe sensing element when stored at room temperature. Based on the data, the amount of measurement drift expected when stored at or near room temperature is negligible. As shown in the graph, even after 3+ years of storage the typical drift is 0.002273°C and essentially a non-factor when compared to other tolerances within the measurement system.
Potential drift (measurement error) is negligible when storing probes at room temperature. When stored at or near room temperature, non-operational temperature probes do not vary from the documented results of the probe’s NIST certification report. The re-certification (calibration) period does not start until the probe is put into service and powered from the sensor control unit.