Features
- Multi-Function Digital Display Unit
- Low-Weight Device Substitutes for Ratemeter
- Simple Switching Between Two Sets of Measurement Units
- Moderated Neutron Detector
- Range: 0 to 99.9 mSv/h (0 to 9.99 rem/hr)
- Display Unit Detaches for Greater Versatility
The Ludlum Model 30-4 joins the Model 30 digital display unit with a 22.9 cm (9 in.) REM ball containing a 3He detector, thereby providing a significant weight reduction and more compact, maneuverable instrument for determining neutron dose rates.Three modes of operation – RATE, MAX, and COUNT – are available for the user. Measurements can be collected in two sets of units (primary and secondary) for RATE and MAX modes in cps, cpm, rem/hr, or Sv/h units. An internal switch is used to enable or disable the front-panel setup feature to protect desired settings from inadvertent modification. Setup is also available via software from Ludlum Measurements.
This instrument features a large, easily-readable LCD (liquid crystal display) that may be rotated for maximum ease of use for the operator. The connecting cable is threaded through the rugged carrying handle to simplify use. In addition the display unit may be detached from REM ball permitting the operator to position the detector and the display unit to best advantage within the limits of the cable length. Other features are an audio warning tone and easy, intuitive, user-friendly design. Splash-resistant construction allows the Model 30 to be used in outdoor environments. The instrument body is constructed of lightweight, durable, high-impact plastic.
| Indicated Use | Neutron dose rate |
|---|---|
| Detector | 3He proportional detector, 1.6 x 2.5 cm (0.6 x 1.0 in.) (D x L), surrounded by a 22.9 cm (9.0 in.) diameter cadmium loaded polyethylene sphere |
| Measurement Range | 0 to 99.9 mSv/h (0 to 9.99 rem/hr) |
| Sensitivity (bare AmBe neutrons) | Typically 10 cpm per μSv/h (100 cpm per mrem/hr) |
| Energy Response | Provides approximate inverse RPG curve for neutrons from thermal through 7 MeV, provides response up to 12 MeV |
| Linearity | Reading within 10% of actual value |
| Gamma Rejection (137Cs gamma) | 10 cpm through 0.1 Sv/h (10 R/hr) |
| LCD Display | 3 digit LCD with large 13.4 mm (0.53 in.) digits, low-battery indicator, MAX, ALARM, MUTE Units: (k)cps, (k)cpm, (µ)(m)Sv(/h), (µ)(m)rem(/h) |
| Display Range |
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| Backlight | Built-in ambient light sensor automatically activates low-power LED backlight, unless internal dipswitch is set to continuous-On (will reduce battery life). Alarm light intensity varies based on ambient light levels. |
| Controls |
|
| Response Time | User-selectable from 1 to 60 s, Auto-Response Rate FAST or SLOW, or Fixed FAST and SLOW |
| Alarms | Count rate, exposure/dose, and scaler alarm setpoints adjustable over the display range |
| Overload | High count rate saturation protection prevents false display of lower count rates |
| Dead Time Correction | Employs first and second order corrections for extended performance |
| Operating Voltage | Approximately 1200 Vdc |
| Threshold | -2 mV |
| Audio | Greater than 75 dB at 0.6 m (2 ft), approximately 4 kHz |
| Click Audio Divide | x1, x10, x100, x1k |
| Power | Two alkaline or two rechargeable “AAA” batteries |
| Battery Life | Approximately 100 hours of operation, 24-hour low battery warning |
| Construction | High-impact plastic with water-resistant rubber seals and separate battery compartment |
| Working Environment | Splashproof shields for outdoor use |
| 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 or IP rating of 52 with audio hole seal option (hole seal option will reduce maximum volume by approximately 10 dB) |
| Size | Display Unit: 8.5 x 8.0 x 4.8 cm (3.4 x 3.1 x 1.9 in.) (H x W x L) Detector: 22.9 cm (9 in.) diameter REM ball with 3He detector (1.6 x 2.5 cm)(D x L) |
| Weight | Display Unit: 174 g (0.38 lb) REM Ball Component: 6.6 kg (14.5 lb) |