A handy and useful Radiation Monitor. (Tools for Environmental Health).

Every once in a while, we buy a piece of equipment for no other reason than anticipation that we might use it for some application in the future. So it was when we purchased a Radiation Alert[R] Monitor 5, manufactured by S.E. International, Inc. * Although it was not an inexpensive instrument--at $375--we wanted a small and portable radiation monitor to supplement our cadre of instruments. No sooner did we have the monitor than we found a wide variety of applications, particularly in our work at colleges and schools.

We first used the Radiation Alert[R] Monitor 5 when we were still performing our own Class II Biological Safety Cabinet certifications using Annex F of NSF Standard 49-1992 (Class II [Laminar Flow] Biohazard Cabinetry). Since many of these cabinets were in laboratories that displayed the universal radiation symbol on the door, we wanted some assurance that we would not put ourselves in harm's way when monitoring air flows, changing HEPA filters, or making repairs. In addition, we usually performed a safety audit of the lab as a courtesy to the principal investigator, which included doing a cursory radiation contamination survey of bench tops, centrifuges, and refrigerators. While wipe-testing is still the preferred method for this type of survey, we can honestly say that we found one or two instances in which we called in the radiation safety officer.

The second application of the Monitor 5 was serendipitous. Of all campus departments, Fine Arts at one time had the most incidents of illnesses and unintentional injuries. While none of the incidents were serious, they did prompt us to action, and we set out to conduct an environmental health and safety audit of all the art facilities. It was quite a surprise when our Monitor 5 started clicking away in Ceramics. Apparently, in the distant past, a uranium salt was used to produce an orange glaze on pottery. The powder was still lurking in the cracks, crevices, and corners of the room and posed an inhalation and ingestion hazard. The Monitor 5 proved itself invaluable during the cleanup efforts. Since then, we use the Monitor 5 regularly in raising awareness of the hazards that might be encountered by antique hunters. Our radiation monitor is an excellent tool for demonstrating the gamma emissions from orange Fiesta ware, "torbenite" crockery, and radium-painted dials on old military watches and clocks.

The monitor proves itself most useful, however, when we get calls from central receiving about damaged or leaking packages. It is an excellent tool for ruling out radioactive materials during hazardous-materials-spill response.

The Radiation Alert[R] Monitor 5 is about as large as our digital light meter or a branch circuit analyzer--roughly 6 inches by 3 inches by 1 1/2 inches--and comes with a nicely designed soft-sided carrying case. It weighs about 9 ounces and runs for about 2,000 hours at normal background radiation levels on a standard 9-volt battery. The unit has a large thin-window Geiger-Mueller (GM) detector located on the back of the instrument that allows for a full view of the 0-to-500- counts-per-minute (CPM) analog scale on the front of the instrument. This large mica window provides for good reproducibility and extra sensitivity to alpha, beta, low-energy gamma, and X-rays. A four-position range switch selects 0-500, 0-5,000, 0-50,000 CPM, or battery power check on the single analog scale, and the on/off switch has a third position for an audio indicator. A single LED provides a visual blip accompanied by an audible signal--which comes in handy in low-light conditions or where our attention is focused elsewhere for safety. The operation manual is well written and provides the necessary accuracy and reference data. It also contains a Beta Activity Determination Chart to determine the activity of a known beta emitter from a measurement with the monitor.

Because this unit measures energy, by its very nature it has to be handled with the same care as a camera. Also, it can sustain damage if subjected to temperature extremes. Therefore, when we carry this instrument in the trunk of our vehicle, we place it, along with our infrared thermometers, in an insulated carryall with a cold pack.

We must admit that this instrument, which we bought because we might have a use for it, has become quite indispensable. We selected the Monitor 5 model because we felt it best suited our needs. S.E. International manufactures several other portable instruments, which you may find have greater applicability Do give the company a call for its latest catalog and price sheet. For what its worth, we recommend that you include a Radiation Alert(r) in your instrument budget.

Government Surplus

Since 9/11, several government surplus instruments have been released for sale. We recently bought two that came complete with the old Civil Defense decal (red CD in a white triangle, set in a blue circle) on a bright yellow metal case. The first is a Model No. lA high-level-radiation meter that reads in Roentgens per hour (P/hr) with four ranges: X100 to X0.1. The second consists of two Bendix pen dosimeters with a reader/charger, also scaled in Roentgens.

These instruments were originally distributed in the 1950s as a response to the possibility of a nuclear holocaust. While they are pieces of history, they also are good training tools and well worth having. They cost us about $70 for the pair and run on D-cell batteries. Both appeared to be in unused condition, but because of their age, it took a bit of tweaking and an emery board applied to the battery contacts to bring them back to life.

Inspection Tip of the Month

Instead of donning a cloth baseball cap during inspections, consider using a white bump cap. While a bump cap is not a safety helmet, it will provide protection against those minor bumps, abrasions, and scrapes so often acquired from large walk-in refrigeration units and overhead dunnage racks in food warehouses. The caps do not look awkward and clean up easily with a mild soap and lukewarm water.

* S.E. International, Inc., P.O. Box 39, Summertown, TN 38483-0039.

Phone: [phone].