Far West Technology, Inc products

FWT-60 series of radiochromic dosimeters are designed for radiation processing. They are thin, colorless films that gradually change to deep blue in relation to absorbed dose. Colorless derivatives of the family of aminotriphenyl- methane dyes can be made radiochromic: that is they will change from colorless to a deeply colored state as a function of absorbed dose. The FWT-60 series of dosimeters use hexa(hydroxyethyl) aminotriphenylacetonitrile (HHEVC) dye. Analysis of the dosimeters is simple using a photometer or spectrophotometer. FWT manufactures Radiachromic readers designed specifically for analyzing its dosimeters. The wavelengths in general use are 510 nm and 600 or 605 nm. Together they cover the whole range of the dosimeter.

FWT-70 series of Opti-Chromic Dosimeters are designed for low level radiation processing. They are small optical waveguides that gradually changes from clear to deep blue in relation to absorbed dose. The sensitivity ranges from 10 Gy to 20 kGy depending on the model. The dye is derived from the family of aminotriphenyl-methane. These dyes can be made radiochromic: that is they will change from colorless to a deeply colored state as a function of absorbed dose. The FWT-70 series of dosimeters use hexa(hydroxyethyl) aminotriphenylacetonitrile (HHEVC) dye inside an optical waveguide. Readout of the dosimeters is by photometric means using dual wavelength photometry.

The “Cypher” is an advanced survey instrument. It is very user friendly and uses digital technology to greatly enhance its operation. It works with most GM, proportional, and scintillator probes and displays the information on a backlit alphanumeric LCD. The display has a moving pointer bargraph that closely approximates a meter movement. It is smooth, easy to read and accurate. The digital level and the bargraph scale are also shown on the display. The instrument has many different modes including rate, integrate, and scaler. Each mode is independently programmable and may be turned off. It can be set up as a simple ratemeter with only one mode or it can be set up for all 6 modes. Thus it can be easily adjusted to suit your application. If that application changes it is easy to reconfigure for a new one. This instrument helps you get the readings you want. It is difficult to misread the data with the units and range information shown right on the display.

The SHADOW is a small, high quality survey meter with a standard 2" pancake GM detector mounted on the bottom. No external probe is needed to do contamination monitoring. Surveying can be done with only one hand and the instrument is small enough to fit in a lab coat pocket. The SHADOW has three linear ranges of 500, 5,000, and 50,000 CPM which are chosen by a three position toggle switch. The scale is also calibrated in mR/h for approximate gamma radiation with ranges of 0-0.2, 0-2, and 0-20 mR/h. The beeper is controlled by the power switch, and the meter light is turned on by a momentary push button. The SHADOW has a unique, “QR” Quick Response feature which eliminates the need for an adjustable time constant. This circuit adjusts the time constant dynamically. When the counting rate increases, the meter will quickly move up scale then slow down as it approaches the true value. The same action occurs if the counting rate decreases: the meter will go down scale quickly then as it nears the true value it will slow down. The feature reduces the statistical meter fluctuations at low counting rates while still responding quickly to significant changes in the counting rate.

The model 1030 is a Pulse Survey Meter. It has been optimized for use in pulsed radiation fields and will measure absorbed dose from any penetrating radiation including x-rays, gamma rays, neutron and high energy particles. It has both rate and integrate ranges. The detector is a cylindrical parallel plate ion chamber with interleaved collection and signal plates. This results in excellent collection efficiency. The detector is constructed of tissue equivalent plastic and the filling gas is also tissue equivalent. The instrument has been tested in fields of 10 Megarads per hour instantaneous with excellent response. If you make beam on measurements in nanosecond fields, you should consider the Model 1030.

The model 2080 Pulse Neutron Survey Meter is designed to measure either pulsed or steady state neutrons. The instrument may be operated as a fixed monitor or as a portable monitor using internal batteries. The microprocessor based instrument displays the dose rate on a digital alphanumeric display. The model 2080 uses the principal of nuclear capture to detect neutrons. The pulsed or steady state neutrons activate silver foil. The resultant beta is measured with a GM counter. A second GM counter subtracts the gamma background. This method of detection allows it to be used to measure very quick pulsed neutron fields. In addition the model 2080 has an alarm capability along with a failsafe relay contact closure for use as an area monitor. A built in horn and light are activated with the radiation level is exceeded. The front panel also has a green, yellow, and red lamp to signify the radiation level at a glance. Also included are a self test capability, front panel lockout, RS232 link and a digital calibration routine. The model 2080 offers all the capability, precision, and reliability that is expected from modern microprocessor based instruments.

The HPI model REM 500 is a small lightweight Neutron Survey Meter. It eliminates the need for a large heavy moderator by measuring the neutrons with a Tissue Equivalent Proportional Counter (TEPC) combined with a 256 channel multichannel analyzer. The instrument applies the appropriate ICRU/P quality factors to each neutron event which results in a true REM response. The REM 500 has all the convenience of a microprocessor based instrument including an alphanumeric display, softkeys, and front panel calibration. It is an easy to use instrument with on screen menus directing the user to the various functions. The display autoranges through a full 7 decades on both RADs and REMs. It has both a rate and integrate mode. The integrate range also displays the integration time in hrs/min/sec. A built in optional check source verifies correct operation and detector calibration. The detector is sealed; this design has been used in the field for over 10 years. The aluminum case is rugged and gasketed. Battery access is through a cover on the end of the case. The Battery life is 100 hours on 6 C cells. The REM 500 Neutron Survey Meter is the ideal instrument to measure neutrons both in the lab or in the field.