Brochure of the LB 9140 and LB 9150 transportable Alpha-Beta monitors
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General
- Real-time continuous monitoring.
- Radon compensation: pseudo-incidence method for LB 9140, spectroscopic selection method for LB 9150.
- Removable monitor with small footprint.
- Modern data acquisition system: data logger with 7” color touch panel and intelligent digital input/output module.
- Si-CAM detector unit 600 mm² for simultaneous separate alpha/beta measurement on a flat dusting area of 25 x 25 mm².
Features
- Fixed filter, quasi-fixed filter or moving filter modes.
- Efficient fixed filter operation: Seamless fixed filter operation with simple filter change option.
- Continuous filter operation with 4 selectable speeds from 5 to 15 mm/h, warning before paper end.
- Step filter operation optionally possible.
- Low-noise and low-maintenance pump unit: External pump unit with low noise level and low maintenance, air flow rate of approx. 3 m³/h.
- Calculations according to DIN EN ISO 11929-1.
Self-Checking & Alarming
- Monitoring of the pump function.
- Monitoring of the filter tape.
- Detector failure threshold alpha and beta (and gamma if installed).
- Pre-Alarm threshold alpha or beta.
- Alarm threshold alpha or beta.
- Lamp test
- Visual and acoustic signals.
The portable monitor consists of the following components:
- Dusting unit: Direct measurement of radioactive alpha/beta particles by means of a Si-CAM detector.
- Alpha/beta detector: Measures directly above the dusting surface to ensure real-time monitoring.
- Cassette: Made of aluminum with IP45 degree of protection, includes the dust extraction unit and filter rolls. A plexiglass front door enables visual inspection of the filter supply on the filter roll.
- Pump unit with free-piston linear motor: The system is quiet and vibration-free. It has the advantage that it is maintenance-free and has a long service life and has a long service life. The nominal flow rate is approx. 3 m³/h with a maximum noise level of 60 dB(A) at 1m distance.
Self test & alarm functions
Continuous monitoring of functionality
The monitor is equipped with self-monitoring functions that continuously check its performance and alarm status:
- Monitoring of the pump function: A deviation of the flow rate from the setpoint triggers a failure message on the evaluation electronics. Even when the pump is switched off, a failure message is also generated.
- Monitoring of the filter tape paper: The rotary coding switch makes it possible to track the amount of filter tape used. At end of the paperroll or if the filter tape paper tears off the message ‘Paper Fail’ is generated.
- Detector failure threshold alpha and beta (also gamma if installed): If the count rate falls below a preset value, an error message (detector failure) is generated.
- Pre-alarm threshold alpha or beta: If the alpha or beta pre-alarm threshold defined by the user is exceeded, an alarm message appeares on the screen.
- Alarm threshold alpha or beta: If an alpha or beta alarm threshold is defined by the user, an alarm message is generated as soon as this threshold is exceeded. Alarms can be set for activity concentrations, emission rates and balance values (Bq/m³ - Bq/h −Bq per day, week, month).
- Relay activation: Every alarm or pre-alarm ca be configured to activate a relay, that can be coupled to an optical or acustical signal.
- Lamp test: Pressing the ‘Lamp test’ switch closes a digital input in the electronics, which in turn triggers and activates all output relays.
Radon compensation
LB 9140
- Compensation by pseudo-incidence method.
- Glass fibre filter.
LB 9150
- Membrane filter.
- The radon compensation method in the LB 9150 ensures the direct measurement of artificial alpha/beta radioactivity with radon follow-up compensation, which utilises the spectroscopic properties of the alpha and beta energy spectrum of the radon and thoron decay products.
- Lower detection limit compared to the LB 9140:
- Three times better in the alpha range.
- Twice as good in the beta range.
- More stable against radon/thoron fluctuations 2 in the indoor air.
Technical Data
| Filtercasette | |
| Construction type | 300 x 300 x 530 mm³ (B x T x H) Operating hours counter, Flow-low and filter fault indicators (LED), Fast filter feed button, Reset button for operating hours counter, Plexiglas door for parts in contact with media |
| Dusting area | 25 x 25 mm² |
| Sampling from inlet to filter | according to DIN 25423 (06/96) Stainless steel RS 316L |
| System losses | < 3.5 % (IEC 60761) |
| Pressure | Surroundings: 650 – 1100 hPa Sample air: max. -150 hPa/ +25 hPa relative to atm. pressure |
| Temperature | Surroundings: -15 / +40 °C Sample air: -20 / +40 °C |
| Filter | |
| Type LB 9140 | Glass fibre particle filter Whatman No. 10, Role 12 m x 50 mm, Winding spool inner diameter 25 mm |
| Type LB 9150 | Fluoropore membrane filter 40mm x 20mm IdNo. 73192 |
| Feed rate | continuous selectable speed 5/10/12,5/15 mm/h Fast feed 1000 mm/h front panel button |
| Autonomy | > 3 months at 5 mm/h speed |
| Pump Unit | |
| Pump | Low maintenance (> 10.000 h) Silent operation (< 60 dB(A) at 1 m) Pump head max. -440 mbar Typical operating -160 mbar |
| Flow rate | Typical 3.3 m³/h with standard condition |
| Controls | Pressure switch (Flow low) Typical setpoint 3 m³/h for standard conditions |
| Alpha-Beta Detector | |
| Type | Si-CAM 600 mm² lightproof |
| Efficiency solid sources | Alpha 241Am typ. 25% / 4 pi Beta 36Cl typ. 25% / 4 pi, 60Co typ. 7-10% / 4 pi |
| Energy sector (Threshold values preamplifier) | Beta: 100 keV – 2.5 MeV Alpha: 2.5 MeV – 10 MeV Alpha Nat.: 7 MeV – 10 MeV |
| Zero effect (System) | Alpha < 0.002 cps, Beta < 0.2 cps |
| Gamma sensitivity | Beta Kanal < 0.4 cps per μSv/h Cs-137 (front) < 0.2 cps per μSv/h (back) |
| Electronics | |
| Type | data logger LB 5340 (Refer to LB 5340 Flyer) |
| Housing LB 9140/LB 5340 | |
| Type | Stainless steel |
| Dimensions | 530 x 300 x 300 mm³ (H x B x T) |
| Protection class | IP 45 (according to IEC 60529) |
| Weight | approx. 43 kg incl. pump & trolley |
| Trolley | |
| Type | Aluminium, RAL5002 paint finish, 2 wheels |
| Dimensions | approx. 1035 x 420 x 395 mm (H x B x T) |
| Alarm unit | |
| Type | LB 9140-ALARM, green light (normal state), orange light and red flashing light, resettable horn 90 dB(A) at 1 m |
| Functions | Horn reset button, lamp test push-button |
| General electrical specifications | |
| Net | 230 VAC / 50 Hz / Single phase, I Norm 1 A Fuse: 1.6 A T, therm. safety 1.3 A |
| Security | EN 60601 conform |
| Radiological | IEC 61172 (in parts), IEC 60761 part 2 |
| EMC | CE conform: EN 61000-4 |
| Subject changes without prior notice. |