The Wipe Test Fixture for Advanced Survey Meter (Model 489-200WTF) uses a high efficiency NaI(Tl) scintillation probe (Model 489-200) in conjunction with a lead shielded sample holder. It employs a removable wipe test holder or tray positioned below the shielded probe. Under these conditions, background radiation is minimized and wipe test counting is maximized.
The wipe test fixture concept evolved from the need to more accurately measure Technetium-99m (99mTc). Most users don’t realize that they are not accurately measuring 99mTc when using a Geiger-Mueller pancake probe. Because of their inherently poor 99mTc efficiency, Geiger-Mueller pancake probes are incapable of accurately measuring 99mTc samples in a timely fashion.
In order to meet current NRC and Agreement state regulations, it would be necessary to count 99mTc samples for a minimum of 30 minutes per sample. The wipe test fixture is designed to precisely measure 99mTc within 30 seconds at efficiencies far surpassing those currently in use. It can count effectively in rate mode and display in any known unit, including “dpm 99mTc or “μCi 99mTc. When used with the ASM-990, or 992 advanced survey meters, the wipe test fixture is able to be calibrated to various other isotopes and thereby expand its role as a wipe test counter.
Effectively detects removable radioactive contamination (wipe testing)
High 99mTc efficiency
Direct reading capability with ASM-990 and 992 Advanced Survey Meters and isotopic calibrations
Removable wipe test sample holder positioned below shielded probe, minimizes background radiation and maximizes wipe test counting