A small, lightweight and portable tritium air monitor
The Model 400AC is a compact and lightweight portable tritium in air monitor with several advanced features, including a gamma compensation on/off toggle switch for straightforward gamma calibration, NiMH rechargeable batteries, RS-232 data output, and automatic calibration software.
With four 200cc ion chambers arranged in a cruciform geometry, the Model 400AC can ensure nearly perfect gamma compensation regardless of photon energy, flux gradient, or flux direction.
Rechargeable b attery and adjustable alarm thresholds
Powered by two “D” size NiMH rechargeable batteries, an LED indicator shows the onset of battery depletion. This LED will also turn red to signal a malfunction with the high voltage power supply.
The front panel features a nine-position alarm level stepped attenuator, which can be adjusted over a range of 2 to 1,000 µCi/m3. If the measurement exceeds the alarm set-point, a steady tone is emitted and the red LED illuminates. Similarly, if the sample airflow is interrupted, the yellow LED lights up and the steady tone sounds.
Drift-free with high sensitivity
Zero adjustment is unnecessary as the electrometer is temperature stable and exhibits zero drift from 0°C to 50°C. This stability is achieved through the careful selection of an ultra-high impedance semiconductor with low internal current leakage and long-term DC stability.
The 400AC can reliably measure currents as low as 10-16 A, with permanently stable span calibration. The ionisation chamber polarising voltage is provided by an electronically regulated, low-noise dual high-voltage power supply (±80VDC). Additionally, the 400AC features proprietary radon recognition and elimination circuitry for accurate, fast, and drift-free measurements.
