These various radiation meters were originally procured and/or used by the NSW government agencies including the former State Pollution Control Commission (SPCC), the Environment Protection Authority (EPA), the NSW Department of Environment and Conservation (DEC), and possibly the NSW Department of Health. These agencies, collectively over the years regulated the use of radiation apparatus (for example x-ray machines used in medical diagnostics) and radioactive substances (for example cobalt-60 used in industrial gauging applications).

The equipment was used to measure the type and intensity of radiation and it exemplifies one of the many aspects of regulation administered by government health departments and augments the Museum's collection of measuring instruments and workplace health and safety material.

Written by Erika Dicker
Assistant Curator, 2007.

S.E. International, Inc. is a small manufacturer of radiation detection equipment for use in industrial, governmental, educational, medical, and environmental markets. They have been producing radiation alert equipment since 1970.

The Monitor 4 radiation detector is a compact general purpose survey meter capable of detecting alpha, beta, gamma, and X-rays over 3 selectable ranges. It is in a small handheld black plastic case. The front of the machine has two switches and a meter in the readout screen. The scale in the readout screen has 0-5µ Sv/hr (sieverts per hour) in the upper scale and 0-0.5 mR/hr (rem) in the lower scale. The range switch consists of three settings: x1, x10, and x100. The whole unit has a leather carry case.

The monitor senses ionizing radiation by means of a GM (Geiger Mueller) tube with a thin mica window. The tube is closed inside the instrument. When a ray or particle of ionizing radiation enters or passes through the tube, it is sensed electronically and displayed by a red light count. When the switch is in the AUDIO position, the instrument will also beep with each radiation event, about 5 to 25 counts at random intervals (depending on your location and altitude) can be expected every minute from naturally occurring background radiation.

Made: 1990 - 2005

2007/60/3

1990 - 2005

145 mm

72 mm

178 g