The HECM 2,
The Helgeson External Contamination Monitor
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| First counting position | Second counting position |
Helgeson Scientific Services has provided the nuclear industry with
high quality instruments and service since 1966. Since 1986 we also
provide the "HECM" - Helgeson Scientific Service's External
Contamination Monitor. This instrument is designed with the same user-friendly
software, high health physics standards, rugged durability, dependability,
and Helgeson's unsurpassed service and warranty. The "PC-HECM" uses a Personal Computer for controlling
all functions. The PC also has the capability of simple and effective
displays of the results, as you will see as you look at our documentation.
The "PC-HECM" is designed to:
- replace manual frisking, with its obvious subjective evaluation of a bouncing meter dial or "popping" sounds from earphones,
and give you superior performance by providing:
- automatic frisking of the subject, which is faster, ensures more complete coverage of the body, and is more reliable in its ability to detect small amounts of external contamination.
More reliable? Why? Because you, the Site Health Physicist, can:
- set action points,
- Type 1 and Type 2 statistical errors (i.e., False Positives and False Negatives),
- measure calibration factors,
and the instrument will:
- automatically measure the background and
- determine the counting time.
The features that make the "HECM" the fine instrument that it
is are a direct result of the evaluation and suggestions of many users
in operating plant environments. The result is an instrument that
meets the true needs of the external dosimetry department and its
procedures.
The "PC-HECM" operation is a two-step measurement with selectable
count parameters based upon site specific and flexible environmental
and counting conditions. The "PC-HECM" meets and exceeds INPO
and NRC guidelines for whole body frisking. We hope you will be as
pleased with the "PC-HECM" as we are to bring it to you.
Features:
- 18 large area gas flow proportional counters
- 3620 square inch active detector area
- 18 Contamination indicator alarm lights
- Puncture limiting grid pattern
- Counter status panel
- Proven sensitivity to 5,000 dpm/100 square centimeters of Cs-137 (Co-60, also) at 3 inches
- Dual position display
- IBM-Compatible Personal Computer
- Front panel test inputs for each channel
- HSS 4-channel PADA0401 and discriminator
- Front panel gain adjustments
- Foot and hand switches insuring correct positioning
- Lightweight: about 650 lbs.
- Portable
- Storage for P-10 tanks
- External start and stop switches
- LED pulse indicators
- Manifold gas-feed system
- RS-232 interface
- Set alarm at count rate above fluctuating background
- Rapid background change rate
- Upper count rate limit/single detector shutdown
- Detector failure/system shutdown number
- False positive acceptance rate
- False negative acceptance rate
The computer also allows the following output:
- Results of each count
- Current parameters/help commands
- Control commands
- Total counts, alarmed counts, "left early" counts
- Current counter status, status changes
- Current count results
Options include:
- Automatic regulator/P-10 tank switch
- Recording gas flow monitor
- Automatic manual override power loss switch
- Remote display monitoring
- Locking plexiglass protective electronics door
- Mass hard disk, floppy data storage, "Zip" disk storage
- Data transmission/dial up
- Remote operation from Helgeson Scientific Sevices for diagnostics and/or training
Complete technical data, physical specifications, and installation
requirements are available upon request. Contact
us here for more information.
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