Model 26-3

High Range Frisker

Part Number: 48-4232

Features

• Integrated, Lightweight Ergonomic Design
• High-Impact Plastic with Water-Resistant Rubber Seals
• Employs Standard 15.51 cm² GM Pancake Detector
• Displays in mR/hr, µSv/h, dpm, Bq, cpm, or cps
• Dead-Time Correction (DTC) Allows Gamma Measurements Up to 1999 µSv/h (1000 mR/hr)
• Simple Three-Button Operation
• Count Rate, Dose/Exposure Rate, and Counting Alarms
• Automatic Display Backlight
• Bright Red Flashing ALARM LED
• Includes Wrist Strap, Clear Pancake Cover & Lanyard

The Ludlum Model 26-3 incorporates electronics and a time-tested GM detector in an ergonomically designed, ruggedly-constructed, and water-resistant housing. The integrated instrument is cable-less thereby simplifying the process of frisking people and objects. The optimized configuration includes a standard 15.51 cm² GM pancake, loud audible “click” output, and large auto-ranging LCD display with automatic LCD backlighting. Model 26-3 has the addition of a Units button that can display measurements in terms of mR/hr, µSv/h, dpm, or Bq. These features are combined in one convenient package making it easier than ever to detect alpha/beta contamination and measure gamma fields on personnel and objects.

Operation of the Model 26-3 is kept simple through the use of just three buttons that are strategically placed for one-handed operation. Three modes of operation RATE, MAX, and COUNT, are available. The RATE mode will display current radiation levels in terms of rate. MAX mode captures the highest rate detected so it is possible to determine a peak rate during frisking operations when the display is not visible. COUNT mode allows the operator to perform a survey for a predetermined time. The user-selected units can display results in a measurement of scaler counts, activity (disintegrations), time-averaged rates, or even accumulated dose. An optional Ambient Dose Filter to correct the energy response is available (part number 2002-1050).

Low-power circuitry means two standard “AA” sized batteries deliver hundreds of hours of instrument operation. The parameters may be protected via internal dipswitch, or the calibrator may allow the user to adjust them. Other features include a backlight triggered by low-level ambient lighting (may be configured for “Continuous On” operation) and a click audio that may be silenced for both RATE and MAX modes.

• Specifications
• Graphs
• Options
• Documents
• Also Available

• Specifications
• Graphs
• Options
• Documents
• Also Available

Specifications

Detector	Pancake GM detector, stainless steel screen (79% open)
Window Area	Active: 15.51 cm2 (2.4 in2) Open: 12.26 cm2 (1.9 in2)
Efficiency	Alpha 239Pu: 11% Beta 99Tc: 14% 32P: 32% 14C: 2% 90Sr/Y: 22% 125I: 0.2% Gamma 5.5 cps per μSv/hr (3300 cpm per mR/hr) (137Cs) 99mTc: ≤ 1%
Display	3½ digit LCD with large 12.7 mm (0.5 in.) digits, low-battery indicator, MAX, ALARM Units: (k)cps, (k)cpm, (k)dpm, (k)Bq, mR/hr, µSv/h, Bq, dpm
Range	0.00 cps to 19.9 kcps 0 cpm to 999 kcpm 0.00 Bq to 19.9 kBq 0 dpm to 999 kdpm 0.00 to 1000 mR/hr 0.00 to 1999 µSv/h
Linearity	± 10%
Backlight	Built-in ambient light sensor automatically activates low-power LED backlight, or may be configured for 'Continuous On' operations (will reduce battery life)
Controls	ON / OFF / QUIET: Press to turn ON; Tap to alternate between click audio and QUIET; Hold for OFF MODE: Alternates between NORMAL (count rate), MAX (captures peak rate), or COUNTER (user-selectable count time from 0 to 20 min.). Each mode is separately programmable so it can be active or turned off. UNITS: Changes units from count rate (cpm, cps) to dose/exposure (µSv/h, mR/hr) to activity (dpm, Bq)
Response Time	User-selectable from 1 to 60 seconds, or automatic FAST or SLOW
Resolving Time	Approximately 110 µs as defined by IEC 60325
Alarms	Count rate and scaler alarm setpoints adjustable over the display range
Overload Protection	High rate saturation protection, indicated by flashing display and audio alarm, prevents false display of lower count rates
Loss of Count Protection	After 60 seconds of no pulses from detector, unit will flash a zero reading and the alarm audio will be triggered
Click Audio	Greater than 60 dB at 0.6 m (2 ft.)
HV Testpoint	Accessible by removing battery cover, allows HV measurement and pulse injection for calibration using optional cable (PN: 8303-1044)
Temperature Range	-20 to 50 °C (-4 to 122 °F) May be certified for operation from -40 to 65 °C (-40 to 150 °F)
Environmental Rating	NEMA 3 / IP 53
Power	Two “AA” batteries
Battery Life	Approximately 1000 hours of operations (as low as 500 hours with backlight configured for 'Continuous On'), 16-hour low battery warning
Construction	High-impact plastic with separate battery compartment, wrist cuff and lanyard included
Distance from Surface Plane to Screen	0.32 cm (0.125 in.)
Size (H x W x L)	4.6 x 6.9 x 27.2 cm (1.8 x 2.7 x 10.7 in.)
Weight	0.45 kg (1.0 lb)

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Graphs

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Options

Option	Description	Part Number
Dose Filter	The GM pancake detector has a significant over-response at lower energies, producing dose measurement errors. The dose filter flattens the response to within ± 20% referenced to 137Cs (662 keV) over the energy range of 20 keV to 1.2 MeV.	2002-1050 (dose filter only) 4519-041-02 (dose filter with tether)
Protective Cover with Tether	Adds tether to the detector protective cover to keep attached to instrument when cover is not in use.	4519-041
Headphone Jack	Adds headphone jack to instrument.	4498-538
Canvas Holster	Canvas holster with belt clip for Model 26 Series instruments.	2312577
Model 180-28	Sample holder for Model 26-Series friskers.	47-3948
Calibration Cable	Allows HV measurement and pulse injection into any Model 26 family of instruments (excluding the Model 26S) from 2019 and later. 99 cm (39 in.) long, C to test pin.	8303-1044
Extendable Pole	A lightweight pole with 5 telescoping sections and an adjustable clamp to hold a Model 26 Series Frisker. Useful to access high, low, or other hard to reach places. Length: 0.55 m (1.8 ft) collapsed, 1.5 m (4.92 ft) fully extended	4519-077
Transport & Storage Case for Model 26 and Extendable Pole	Rugged, waterproof, airtight, hard-shell case with dense foam padding to hold Model 26 and extendable pole.	2311064

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Documents

• Data Sheet
• Dose Filter Data Sheet
• Product Manual
• CE Certificate
• Model 26 Series Comparison Table

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Also Available

Description	Part Number
Model 26-3 with Dose Filter	48-4233

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