Calibration Shelf Life and Storage Conditions?

I just received this question by email and wanted to open it up to Emerson flow experts in this track for comment:

I have a general question about flowmeter calibration intervals. We use electromagnetic, Coriolis, and vortex flowmeters in [application removed to protect confidentiality]. Internally, we have requirements that define default flowmeter calibration intervals as 12 months unless justified otherwise. We are familiar with the pain and disruption involved with periodic flowmeter calibrations.

One situation that commonly arises is when we use a flowmeter for testing, remove it and have it recalibrated and returned to us, then the flowmeter sits on a shelf for a few years unused; then we decide to use the flowmeter in a new test. Since that last calibration was more than 12 months ago, by default, the calibration is considered to be expired. However, most flowmeter vendors agree that if the flowmeter is properly stored during that idle time and is not damaged or dropped, the calibration should be as “fresh” as the day it left the calibration facility; i.e., it is service time and service conditions that cause calibration drift, not storage time. In that case the calibration interval “clock” should not start until the unit is actually put into service.

I believe I can make that case with confirming statements from the OEMs that make the flowmeters. However, what I think I need to define more clearly is what those acceptable storage conditions are – hard numbers stating temperature and humidity ranges for example.

Is that information published by Emerson?

Thanks in advance for any feedback you have.

1 Reply

  • Considering the electronics within flow meters, perhaps it is good to get it calibrated again in case of long shelf life.
                                                                                                                                                                                              
     
    From: Jim Cahill [mailto:bounce-Jim_Cahill@community.emerson.com]
    Sent: 06 November 2012 16:32
    To: Flow@community.emerson.com
    Subject: [EE365 Flow Track] Calibration Shelf Life and Storage Conditions?
     

    I just received this question by email and wanted to open it up to Emerson flow experts in this track for comment:

    I have a general question about flowmeter calibration intervals. We use electromagnetic, Coriolis, and vortex flowmeters in [application removed to protect confidentiality]. Internally, we have requirements that define default flowmeter calibration intervals as 12 months unless justified otherwise. We are familiar with the pain and disruption involved with periodic flowmeter calibrations.

    One situation that commonly arises is when we use a flowmeter for testing, remove it and have it recalibrated and returned to us, then the flowmeter sits on a shelf for a few years unused; then we decide to use the flowmeter in a new test. Since that last calibration was more than 12 months ago, by default, the calibration is considered to be expired. However, most flowmeter vendors agree that if the flowmeter is properly stored during that idle time and is not damaged or dropped, the calibration should be as “fresh” as the day it left the calibration facility; i.e., it is service time and service conditions that cause calibration drift, not storage time. In that case the calibration interval “clock” should not start until the unit is actually put into service.

    I believe I can make that case with confirming statements from the OEMs that make the flowmeters. However, what I think I need to define more clearly is what those acceptable storage conditions are – hard numbers stating temperature and humidity ranges for example.

    Is that information published by Emerson?

    Thanks in advance for any feedback you have.