A modified impinger for personal sampling

The performance of a modified impinger is described. Laboratory and limited field studies found that the modification made the device relatively spill-proof. In addition, the collection efficiency of the spill-proof impinger was compared to the standard midget impinger. For particles larger than 0.8 micrometer equivalent aerodynamic diameter, the impaction efficiencies of the two devices were found to be identical. However, the capture efficiencies of the two devices were not always found to be equivalent. In three tests, the modified impinger collected proportionately more material than the midget impinger. In three other tests, the capture efficiencies of the two devices were found to be equivalent.