ASTM recommends a calibration of your gauge every 12 months. Calibrations are necessary due to the decay of the gauge Cs137 density source.

You should request a new calibration after a repair that involves electronics or GM tube replacement. It is the “drift” in electronics and the GM tubes that are also a top reason for needing a recalibration. Rough treatment of gauges can also impact calibration.

Any dispute between a gauge that has been properly calibrated vs. a gauge that is outside of calibration will generally be settled on the side of the properly calibrated gauge.

A properly calibrated gauge should work fine provided you perform timely standard counts. Take a standard count every day you use the gauge. Some manufacturers recommend several standard counts throughout the day, perhaps every few hours or as the materials being tested change.

If your gauge has not been used for over 2 months you will want to re-establish your standard count averages. To do this you need to take 4 new standard counts and then compare subsequent standard counts to the average of those 4 counts.

Many service centers offer “winter specials”. These specials are designed to entice you into sending your gauge in during the winter months when gauge operations slow down or halt due to the colder climate. It is beneficial to have your gauge worked on during this time of inactivity and it can save you money, sometimes as much as $200.00. Keep in mind that many companies wait until the “thaw” before sending their gauges in and this can result in longer lead times.

You can save a lot of money by shopping around for service. The aforementioned winter specials only last a couple of months and the same service during the summer will cost you a couple of hundred dollars more. Other service centers offer a standard price throughout the year and this price is much more attractive during the months when you are actually using the gauge.

When shopping for service keep in mind the shipping costs and gauge turn-around. If time is critical go with a highly qualified service provider with timely turn-around. The only thing worse than having a gauge go down in the middle of a job is getting a gauge back from service that has not been properly repaired.

Basic gauge calibration service does not include other types of gauge repair and damage. Get a verbal quotation as to the expected costs of other gauge repairs. If the service provider cannot give you a specific quotation you will want to ask for a general parts list with pricing as well as labor charges. You may be surprised how much you can save comparing one service provider to another.

When shipping a gauge in for service make sure to fill out all necessary Return Goods forms as well as any regulatory forms for transfer of radioactive materials. The service center should be able to help you with shipping and forms.