Overhoff - Model 200SB and 200SB HTO -Portable Tritium Survey Monitor
The Model 200SB is a low-cost, lightweight, portable tritium in air monitor. A rapid warmup, high-volume rotary vane pump, and fast electronics combine to give this tritium monitor a very quick overall response time of just 5 seconds or less. The Model 200SB uses two coaxial 200cc ionization chambers, one for measurement and one for gamma compensation. The 200SB is our economy model, with medium sensitivity, a wide range, and very fast response. Particularly useful as an emergency tritium monitor due to compact size and rapid warmup and response.
Power is supplied by a pair of “D” size alkaline batteries. Onset of the battery depletion is signaled by illumination of an LED located next to the meter face. A nine-position alarm level stepped attenuator, adjustable over partial scale (.01 – 5%) is located on the front panel. A steady tone is emitted by an acoustic signaler if the measurement exceeds the alarm set-point (illuminates red LED), or if the sample airflow has been interrupted and is too low (illuminates yellow LED). The alarms are non-latching.
Zero adjustment is unnecessary, the electrometer is completely temperature stable and shows zero drift from 0° C to 50° C due to special design and careful selection of an ultra-high impedance semiconductor with low internal current leakage and long-term DC stability. The 200SB can reliably measure currents as low as 10-16 amperes and the span calibration is permanently stable. The ionization chamber polarizing voltage is supplied by an electronic low-noise regulated dual high-voltage power supply (±80VDC). The 200SB includes proprietary radon recognition and elimination circuitry to provide accurate, fast, and drift-free measurement.
- Lightweight, compact portable tritium air monitor
- Extremely fast response: 5 seconds to reach 90% of final value
- Rapid warm-up of less than 30 seconds
- Coaxial gamma compensation (200cc volume)
- Medium sensitivity: 10 µCi/m3, 1 MPCa, or 0.4 MBq/m3
- Wide range: 10 to 199,990 µCi/m3, 0.1 to 1,999.9 MBq/m3, or 1 to 19,999 DAC/MPCa
- Audible and visual alarm indicators for low flow, low battery, and signal level
- Alpha pulse suppression, radon rejection
- No long-term drift, no manual zero adjustments
- Offset potentiometer control included
- CE Marked
- MEASUREMENT RANGE : 10 – 199,999 µCi/m3
- Other available measurement ranges:
- 0.1 to 1,999.9 MBq/m3
- 1 to 19,999 DAC or MPCa
- SENSITIVITY : 10 µCi/m3 (1 MPCa or 0.4 MBq/m3)
- DISPLAY : LCD panel meter
- ACCURACY, SPAN : ±10 % of reading, ±10 µCi /m3, whichever is greater
- NOISE LEVEL : ± 10 μCi/m3, 1 S.D. (3 second electronic time constant)
- ZERO STABILITY : after 1 minute (or less) warm up, zero drift less than ± 10 μCi/m3
- GAMMA COMPENSATION : chambers in a side by side pattern reduce errors due to external gamma radiation.
- RESPONSE RATE : 5 seconds to reach 90% of final reading
- ALARM (ACOUSTIC) : Nine position stepped attenuator set point for signal alarm
- 20 – 10,000 µCi/m3, steady tone.
- Low flow produces a steady tone
- ALARM (VISUAL) : signal level: red LED
- low flow: yellow LED
- low battery: red LED
- EXTERNAL CONNECTIONS : not available
- IONIZATION CHAMBER VOLUME : effective volume: 200 cm3
- port to port volume: 220 cm3
- DUST FILTER : external in-line disposable cartridge type P/N 12082
- PUMP : special high volume internal rotary vane pump
- FLOW RATE : nominally 2-3 LPM
- ENVIRONMENTAL : 0° C to +50° C, 0 – 95 % relative humidity non-condensing
- BATTERIES : two “D” size batteries, alkaline
- SIZE : 7.6″ L, 5.2″ W, 4.4″ H excluding handle
- WEIGHT : 5 lbs (2.3 kg)
- Accessories included: : • 2 “D” Size Alkaline batteries
- • Sniffer hose
- • Dust filter
- • AC Power converter (optional)
- • Carrying case (optional)
- Jack for external AC power adapter (includes power adapter for 100-240VAC, 50/60 Hz)
- Hard Plastic Protective Carrying Case