Frequently Ask Questions

Smoke Detectors: Some smoke detectors contain a sealed radioactive isotope as part of the smoke sensing mechanism. There is no danger to the individual if the container in sealed. They are labeled. Camping Lantern Mantles: In recent years this has changed but some lantern mantles are made with radioactive Thorium. Be especially careful not to inhale or ingest the fine ash that is left when they are burned out. Clocks, Watches, and Timers: Many old timepieces have dials painted with radium to make them glow in the dark. Tritium is now commonly used to obtain the same effect. Tritium is also radioactive but emits low energy radiation which cannot penetrate the lens of the timepiece. Jewelry: Some gold used to encapsulate radium and radon for medical purposes was improperly reprocessed and entered the market as radioactive rings and other types of gold jewelry. Some imported cloisonné being glazed with uranium oxide exceeds U.S. limits. Some gems are irradiated by an electron beam or in an accelerator to enhance their color. Irradiated gems typically are held until there is no residual activity remaining. Rock Collections: Many natural formations contain radioactive materials. Hobbyists who collect such things should vent the rooms in which these items are stored and be careful to avoid inhaling the fine dust particles from these samples. Pottery: Some types of pottery are glazed with uranium oxide, such as Fiesta ware. To the best of our knowledge, this process has been discontinued, although some of these pieces are still in circulation.

No. It runs on piezo electric charges.

Each model has 5452 data points available in the on-board memory. This means, for example, that you can record 3.79 days worth of data if you have chosen to record data in 1 minute intervals. To break it down, 1 save per minute is 60 saves per hour. 60 saves over a 24 hour period is 1440 saves. 5452 divided by 1440 is 3.7 days.

If you would like to record readings for a longer period of time, then change the unit to record less frequently. For example, changing the data logging frequency to every 10 minutes will give you 37 days worth of readings. 1 save per every 10 minutes is 6 saves per hour. 6*24=144 saves. 5452 divided by 144=37 days.

The on-board memory records the time and date with each reading. In addition, the data reflects the total counts collected during the chosen time interval, the highest and lowest rate in that time frame and the second in which each happened during the selected time internal. This means that if you selected to record data every 5 minutes, you will see the data during that 5 minute interval. Here's an example: [su_table responsive="yes"]

Date	Time	Total (Counts)	Interval (Minutes)	Highest (cpm)	Hi Time (seconds)	Lowest (cpm)	Lo Time (seconds)
1/2/2014	17:21	163	5	48	103	18	10

[/su_table] Download Observer USB Sample Data

It all comes down to user preference. Technically, you can use up the whole range of the pen dosimeter and recharge it then. That would mean that a person would have to record the last reading after use and use that last reading as the zero when the use it again, tracking any changes between the two. However, the more common practice is to recharge them and bring the reading back to zero after each use.