Frisking people and objects for alpha & beta contamination has always been a little awkward because manipulation of the cable, detector, and electronics required the use of both hands. The new cable-less Ludlum Model 26 consolidates the electronics and the detector into one ergonomic housing. This optimized configuration incorporates a standard 15 cm² GM pancake probe, loud audio “click” output, and large auto-ranging LCD display with automatic back lighting into one convenient package, making it easier than ever to detect contamination.
Operation is kept extremely simple through the use of just two buttons. A useful feature employed in the design is the MAX mode, which captures the highest or peak count rate. It is particularly convenient whenever the display is not directly visible. The scaler mode, with a preset count time, allows the user to take a discrete measurement. This system also incorporates low power circuitry, delivering hundreds of hours of use with just two standard “AA” size batteries. The calibrator can protect parameters (cps/cpm, response time, alarm points, & scaler time) or allow the user to adjust them.
DETECTOR: pancake GM (Geiger-Mueller) detector, stainless steel screen
WINDOW AREA: Active: 15 cm² ( 2.3 in²); Open: 12.2 cm² (1.9 in²)
EFFICIENCY (4 π): Alpha: 15% for 239Pu; Beta: 19% for 99Tc; 32% for 32P
Gamma: 3300 cpm/mR/hr or 5.5 cps/μSv/hr (137Cs)
ALARMS: count rate and scaler alarm setpoints adjustable over the display range
OVERLOAD: high count rate saturation protection prevents false display of lower count rates
LCD DISPLAY: 3½ digit LCD with large 12.7 mm (0.5 in.) digits, cpm, cps, low battery indicator
RANGE: 0.1 cps to 1.99 kcps, or 1 cpm to 99.9 kcpm
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: two pushbuttons
OFF/ON/QUIET: press to turn ON, tap to alternate between click audio and QUIET, hold for OFF
MODE: alternates between Normal (countrate) and Max (captures peak rate), and Scaler (user-selectable preset count time from 0 to 20 minutes). Each mode is separately programmable so it can be active or turned off.
RESPONSE TIME: user-selectable from 1 to 60 seconds, or automatic FAST or SLOW
CLICK AUDIO: greater than 60 dB at 0.6 m (2 ft)
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
SIZE: 4.6 x 6.9 x 27.2 cm (1.8 x 2.7 x 10.7 in.) (H x W x L)
WEIGHT: 0.45 kg (1.0 lb)