WHAT'S THE DIFFERENCE BETWEEN SURVEY METERS, GEIGER COUNTERS AND DOSIMETERS?

Survey meters, field survey meters, rate meters, radiac meters, radiation detection meters, low-range meters, high-range meters, airborne meters, fallout meters, remote monitors, Geiger counters, and even 'dose rate meters' are all describing instruments that measure exposure rate or the intensity of radiation at a location at some point in time. It's like the speedometer of a car; both present measurements relative to time. All of these above 'meters', the Geiger counter, too (which utilizes a Geiger tube rather than an ion chamber), will show their radiation intensity readings relative to time, such as R/hr or mR/hr like the scale at the right, same as a car speedometer will show miles/hr. If you entered a radioactive area and your meter says 60 R/hr then that means if you were to stay there for a whole hour you would be exposed to 60 R. Same as driving a car for an hour at 60 mph, you'd be 60 miles down the road after that hour, at that rate.

Close-up of Civil Defense Survey Meter

Dosimeters, which are also available in high or low ranges, can be in the form of a badge, pen/tube type, or even a digital readout and all measure the total accumulated amount of radiation to which you were exposed. (The Civil Defense pen/tube type would show a reading like at the right when looking through it.) It's also similar to the odometer of a car; where both measure an accumulation of units. The dosimeter will indicate a certain total number of R or mR exposure received, just as the car odometer will register a certain number of miles travelled. More in-depth details regarding dosimeters follows below in the section entitled; What about Dosimeters and Chargers?

Close-up of Civil Defense Survey Meter

Example of the relationship between a survey meter and a dosimeter

If you had a survey meter in one hand and a dosimeter in the other and walked into an area of measurable radiation and your survey meter said you were now standing in a 30 R/hr radiation field, and you stayed there for two hours, then your dosimeter at the end of those two hours would be indicating 60 R. The meter measured the exposure rate or intensity of the radiation there and the dosimeter accumulated the total amount of radiation you had been exposed to for having been there those two hours. (If you had left right after the first half-hour, then your dosimeter would have been reading only 15 R.)

Bottom Line: Both meters and dosimeters have their place, and their limitations, in indicating the presence of hazardous radiation levels, and when utilized by a person with the basic understanding of what they are each measuring, they can be critical life-saving tools to survival in a nuclear emergency.