Model 194 Series
User’s Manual
Section 1
Ludlum Measurements, Inc.
Page 1-1
October 2020
Introduction
he Ludlum Model 194 DOSE EQUIVALENT RATE
METER is designed to accurately measure gamma radiation
doses. It utilizes a special plastic scintillator that converts the radiation to
visible light, which is then measured and displayed. It is very sensitive and
can measure background levels of radiation as well as higher levels.
The Model 194 is similar to a Micro R meter in sensitivity, but has a flat
energy response and measures ambient dose equivalent, not exposure.
Most Micro R meters utilize sodium iodide (NaI), which over-responds
to many common gamma ray energies, causing incorrect high readings.
The Model 194 measures dose, specifically ambient dose equivalent, and
has a response that is relatively flat over the most common gamma ray
energies. See Figure 1.
Figure 1. Energy Response Comparison
T
Section
1
