3078 Series Stretch Scope

Ludlum Measurements

3078 Stretch Scopes 3078 meter controls 3078 meter controls


The Model 3078 and 3078i Stretch Scopes are designed to survey areas for gamma radiation while maintaining distance from potentially high radiation fields. Both instruments include external GM detectors mounted at the end of a 4.7 m (15.3 ft.) carbon fiber telescoping pole, allowing the detector to reach areas difficult to access with other types of instruments. The Model 3078i has an additional internal GM detector for monitoring user dose exposure.

The meter body is made of durable, high-impact plastic with splash-resistant construction for outdoor use. The instrument has a large, easy-to-read LCD with a backlight that adjusts to changing ambient light to provide optimum viewing in any conditions. User-adjustable audio levels provide the operator with audible clicks and alarms across all modes of operation.

Each Model 3078 Series instrument has four modes of operation (RATE, MAX, COUNT, and DOSE) selectable using the MODE button. Measurements can be collected in two sets of units (primary and secondary) for all modes of operation by pressing the UNITS button. The external detector can operate in LOW, HIGH, or AUTO range modes by pressing the DET button. With data logging enabled, a simple press of the LOG button will record and time-stamp the current reading. Each instrument can store up to 1000 data points. On the Model 3078i, the internal detector runs continuously and reports accumulated dose measurements, which can be viewed at any time by pressing the PRG button.

Detector External: Two energy-compensated GM tubes
Internal (Model 3078i Only): One energy-compensated GM tube, Range: background to 50 mSv/h (5 R/hr)
Energy Response Within 25% of true value from 60 keV to 3 MeV
Linearity Readings within 10% of true value
Display Three-digit auto-ranging LCD. Units: (μ)(m)(k)(M)R(/h), (μ)(m)(k)(M)Sv(/h), (k)cps, (k)(M)cpm. Indicators: bar graph, mode (MAX, INTG), three alarm levels, fault messages (FAULT, OVERLOAD, LOSS OF COUNT, OVERRANGE), USB, wireless, audio, and low-battery.
Display Range 1 µSv/h to 10 Sv/h (0.1 mR/hr to 1000 R/hr)
Range Selection
LOW range (1 µSv/h to 20 mSv/h, or 0.1 mR/hr to 2 R/hr);
HIGH range (8 mSv/h to 10 Sv/h, or 0.8 R/hr to 1000 R/hr);
or AUTO range across full display range
Display Backlight Built-in ambient light sensor automatically activates LED backlight unless internal dipswitch is set to continuous-on (will reduce battery life)
User Controls
ON/AUD: Extra-long press to turn ON; Tap to adjust audio level; Extra-long press to turn OFF
UNITS: Changes the units between count rate, dose/exposure, or disintegration
DET: Tap to change external detector to operate on LO, HI, or AUTO range; Extra-long press to switch between external and internal detector (3078i only)
LAMP/MODE: Short press alternates between RATE (count rate), MAX (captures peak rate), COUNT (user-selectable preset count time from 0 to 2775 hours), and DOSE (current accumulated dose); Extra-long press enables lamp on end of stretch scope detector
Response Time User-selectable from 1 to 60 seconds, auto SLOW, auto FAST, fixed SLOW (22 s), fixed FAST (4 s)
Alarms Three count rate, exposure/dose, count, and accumulated dose alarm set-points adjustable over the display range
Overload Protection High count rate saturation protection designed to prevent false display of lower count rates. If the instrument detects an overload condition, OVERLOAD will appear on the display and an audio warning will be triggered.
Loss of Count Protection After 60 seconds of no pulses from the detector, the instrument will flash a zero reading, an audio alarm will be triggered, and LOSS OF COUNTS will appear on the display
Overrange If the reading exceeds the predefined detector range, the instrument will flash a maximum reading, an audio warning will be triggered, and OVERRANGE will appear on the display
Audio "Click" audio greater than 65 dB at 0.6 m (2 ft.)
Alarm audio greater than 72 dB at 0.6 m (2 ft.)
Calibration Protection Internal dipswitch to disable front-panel calibration parameter changes
Power Four "AA" batteries
Battery Life Approximately 75 hours with no backlight (as low as 20 hours with backlight and lamp continuous-on), 16-hour low battery warning
Construction High-impact polycarbonate with rubber seals and separate battery compartment attached to telescoping carbon fiber pole
Temperature Range -20 to 50 °C (-5 to 122 °F)
May be certified for operation from -40 to 65 °C (-40 to 150 °F)
Environmental Rating
NEMA rating of 3x
IP rating of 53
Size (H x W x L) 20.0 x 11.4 x 125.1 cm (7.9 x 4.5 x 49.25 in. [4.1 ft.]) retracted, fully extended length 466.7 cm (183.75 in. [15.3 ft.])
Weight 2.5 kg (5.4 lb) including batteries and shoulder strap