Aware Electronics Radiation Monitors Independent Tests

Aware Electronics exclusive radiation monitor design provides detection capabilities 1000 Times Higher than many of our competitors.

Independent testing has revealed a large advantage of Aware Electronics Radiation Monitors over and above many of our competitors. With high level rising radiation fields, as would occur near a nuclear incident, the Aware monitors continue to display increasing viable radiation readings while the competitor’s radiation monitors display a falling radiation level and finally read zero radiation levels. This fall-off to a zero reading occurs at a radiation level 1000 times less than levels where the Aware monitors continue to display rising radiation levels.

The testing was performed using a precision digital readout microfocus spot X-Ray probe tester. Radiation levels were confirmed using a RAD-CHECK PLUS X-ray Exposure Meter.

Summary of the test:

Normal Monitor 4 and Inspector type radiation monitors quit (read zero) at below 0.001 R/H. (Totally saturates at 9.5 uA beam current).
Aware Electronics radiation monitors work (do not saturate) to at least 1.42 R/H, which is the strongest radiation field the microfocus spot X-Ray probe tester could generate.

An Aware RM-60 with LND 712 tube feeding a standard serial port with standard software running on a standard PC was tested several years ago by the Dept. of Homeland Security. They exposed the RM-60 to a 2 million microR/hr. (2 R/H) gamma field and the RM-60 and software continued reporting viable readings of 2 million microR/hr. with no sign of saturation. Also see: The increased sensitivity of the RM-80 and its immunity from saturation

Exclusive Discriminator

Aware Electronics monitors include an exclusive discriminator which allows the accurate display of radiation levels well in excessive of what one would expect given the tube data sheet. When developing our circuit, we designed and tested several hundred variations and finally settled on the best performing. All active components are rugged silicon devices very resistant to radiation and burn-out. Power draw is ~ 0.08ma at background levels and rises very modestly with very high radiation fields. The circuit operates with input voltages anywhere between 2VDC to 20 VDC. The fully regulated high voltage section maintains a constant high voltage with extremes of input voltage and radiation levels. The resulting design represents an entirely original circuit available exclusively in Aware's monitors.

The take home message is when you most need a radiation monitor’s abilities due to rising high-level radiation levels, many of our competitor’s monitors will show falling radiation levels that finally reach zero while Aware Electronics monitors will continue to display rising, viable radiation levels.

Exclusive High Voltage Power Supply

An important part of any Geiger counter circuit is the high voltage generator. Most of Aware’s competitors use a very simple technique to generate the high voltage known as a boost converter. This involves an inductor in series with a transistor switch and a diode. The transistor is turned on and off by a control circuit. An advantage of the boost converter is it does not utilize a custom step-up transformer but rather utilizes a very simple and cheap inductor.

Typical Boost Converter

Boost Converter On Stage Boost Converter Off Stage
The key principle that drives the boost converter is the tendency of an inductor to resist changes in current by creating and destroying a magnetic field. However, the boost converter has a serious disadvantage. The transistor will have to handle both a high current when the transistor is on and a high blocking voltage when the transistor switches off. The peak transistor voltage is equal to the dc input voltage plus the reflected load voltage and this can amount to several hundred volts. In practice, additional voltage is observed due to ringing associated with the leakage inductance. Such repetitive voltage spikes can slowly damage the transistor.

We have analyzed various competitor boost converters with an oscilloscope and notice they subject the transistor to repeated voltage spikes near or even above their absolute maximum rating. This can lead to degradation and breakdown of the transistor over long periods of time even if operated somewhat below the absolute maximum rating. Even a competitor’s boost converter with a four stage diode multiplier generating 500 VDC, produces 200+ volt pulses on the transistor.

Aware Electronics Corp. uses a different technique for generating the high voltage necessary. We have custom designed a miniature high voltage transformer which includes three windings, a primary, secondary and feedback winding, allowing us to create our unique, fully regulated very high efficiency high voltage harmonic oscillator power supply.

Aware's harmonic oscillator utilizes the natural rhythm of the transformer’s inductance and a capacitor to step-up the low voltage source to a high voltage by-way-of the turns ratio of the primary to secondary. The primary winding of our transformer includes approximately 8 turns and the secondary includes over 2000 turns, thereby stepping up the voltage needed with just two diodes, even with a 1.5 volt input. (Input voltage can range from 1.5 to 20 VDC). Aware's new HV harmonic oscillator is also very low noise due to the transformer's primary winding tank circuit.

All active components of the high voltage generator are rugged bipolar silicon devices, including the components in the regulating sub-system. Many competitor systems utilize mosfets which can be very sensitive to voltage spikes.

Aware's Custom Miniature High Voltage Transformer With Enhanced Design as of May 2015 (12mm x 12mm)
Transformers Available for Purchase in Lots of 1 to 1,000. Phone or write for details.

Aware's Custom Miniature Transformer

Aware's Original Transformer
Aware's Miniature Custom Transformer

A major advantage of Aware’s high voltage feedback oscillator: The transistor is exposed to only the supply voltage (1.5 to 16 VDC) rather than the several hundred volts of the boost converter technique. Aware Geiger counters, with our custom high voltage generator, have been running continuously now for over 27 years and not a single transistor has failed.

Power Transistor Crystal Damage in Inductive Load Switching: A Reliability Concern. International Business Machines Corporation, Poughkeepsie, N. Y.

A high-voltage n-p-n--n+ type power transistor switching an inductive load for approximately 1000 hours showed no significant variation in the electrical parameters. Infrared scanning, and cross-sectioning and visual inspection of the chip indicated a crystal damage at the n--n+ interface under the center of the emitter. Transmission electron microscopy (TEM) investigations revealed the crystal damage to consist mainly of silicon phosphide precipitate platelets surrounded by dislocation loops and dislocation clusters. An analysis using a two-dimensional mathematical model predicts high electrical and thermal stresses at the damaged location of power transistor during its switching applications.

Conclusion: For longevity and high accuracy choose Aware Electronics line of Radiation Monitors and software.

Transformers Available for Purchase in Lots of 1 to 1,000. Phone or write for details.
Aware's Miniature Custom Transformer

Aware Electronics fully regulated HV generator and discriminator circuit boards available for purchase. Three wire interface: Power supply in plus, minus and signal out. Anode and cathode for Geiger tube(s). 500VDC. Jumpers for 400VDC and 300VDC. Connect plus and minus to your project’s plus and minus (3VDC to 16VDC) and connect signal out directly to your project’s interrupt or counter pin. $59.95 each. Add $12 for HV output wires and HV potting. Phone or write for details.
Aware's Discriminator HV generator Aware's Discriminator HV generator

Click here for a Comparison of Aware Electronics Corp. LCD-90 + RM-80 to the Inspector EXP Probe Model

Click here for a Comparison of Aware Electronics Corp. LCD-90 + RM-80 to the Mazur PRM-9000

Aware Electronics Tests BlackCat Software and GeigerGraph. Using Monitors with the same type tube, Aware Electronics Software can measure radiation levels Ten Times Higher than BlackCat's system or any monitor using GeigerGraph software: Aware Electronics Tests BlackCat Software and GeigerGraph

Aware Electronics RM-60 Versus Digilert: Aware Electronics RM-60 Versus Digilert

We have analyzed a Geiger counter by SparkFun: A look at SparkFun Geiger Counter

We have tested software by others and are surprised by the results. Click here to read about it: A look at a system by others

For the last 20+ years our goal has been and is to provide the best solution for radiation monitoring.

Phone:(800)729-5397 or Phone/Fax: (302)655-3800

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