The SmartION is an advanced microcomputerbased instrument for the measurement of Gamma, Beta and X-ray radiation. It provides functions previously not available in meters of this type, including data logging, alarm, remote calibration and security features. Operation is simple, reliable and maintenance-free, and the instrument is housed in a robust case.

The instrument’s ion chamber has a capacity of 450 cm3. Measurement in mixed beta/gamma fields is simplified by the moveable beta shield, which is 550 mg cm-2 plastic. The Ambient Dose Equivalent (Sv -1) version is corrected for a response of H’(0.07) from 10 keV with the shield open and H*(10) from 22 keV with it shut. The 7 mg cm-2 window density permits accurate measurement of beta dose rates in the energy (Emax) range of 150 keV to 2.5 MeV.

The chamber is vented to the air volume within the instrument and thence to atmosphere.

The electrometer is based upon a low-leakage MOSFET operational amplifier. Special guard-ring techniques and packaging pin-out keep offset leakage to a minimum. Careful matching and circuit design minimize zero drift with temperature. Zero adjustment is established by microcomputer control: pressing the Zero button engages a precision digital servo loop adjustment.

There are three SmartION models: the basic version is the 2100; the 2120 has an integrating dose facility; the 2140 has in integrated barcode reader. Each of these models is available to measure the quantities ambient dose equivalent rate (Sv), air kerma (Gy) and exposure (R). In each case the ion chamber is configured at the time of manufacture.

Dose rate data from random surveys can be stored in up to 400 storage locations. Ordered location surveys are organized by downloading 4-character locations before issue from a PC file (ASCII) through a serial cable which is supplied with the PC software option. The memory inside Smart-ION in non-volatile through switch-off, as is the internal clock.