 Some of the oldest and most widely used types of radiation detectors are based on the effects produced when a charged particle passes through a gas.
 Ion chamber instruments are, in principle, the simplest and therefore most reliable of these detectors.

(OVER) SIMPLIFIED VERSION
 As a fast, charged particle passes through a gas, it interacts with neutral molecules resulting in an ion pair (positive ion and free electron).
 This can occur by direct or indirect interaction.
 The number of these interactions is a remarkably constant parameter given the gas and type of radiation.
 In the presence of an electric field, the ion pairs will migrate or drift.
 This drift of ion pairs creates an electric current, which can be measured.

 The ion chamber is the standard workhorse of portable ion chamber survey instrumentation.
 Used to determine dose rates and thereby stay times
 Essential to ensuring safe work environments.
 Eberline Services has been working to redesign this instrument, keeping the full functionality and familiar look and feel while making the unit safer and more user friendly.

 Assume that the ion chamber instrumentation can be updated and improved
 Get input from users; ESI has a large internal pool of users in our own RCTs and IHTs
 Insert new electronics and improve data processing
 Reduce weight
 Move beyond survey usage
 Enhance data collection
 Use ESI background in field applications and other developments, e.g. field surveys, GPERS, etc.

 GPERS composite technologies are continually updating and improving.
 Miniaturization of individual modular components of the GPERS system has allowed the weight burden to be reduce to < 8 pounds!
 Surveyor safety is improved greatly with its lightweight and diminished size (integrated system almost unnoticeable for surveyor and allows near uninhibited agility).

 Data is collected or monitored:
 Locally to a data logger with display to monitor a trace of his survey path and current radiological readings in realtime to verify coverage of any given area. Areas that exceed a user-set radiological trigger point activate an audio cue and are visually highlighted to provide instant notification.
 Transmitted via Bluetooth® to a local wireless network/cloud.
 Real-time data classification and analysis can be conducted remotely and simultaneously with field teams.

 Lightweight yet rugged and with improved accuracy.
 All system components performed without incident while surveying robotically in a 150 R/hr area.
 Improved data accuracy quality in a quicker time frame makes “informed” project managers resulting in better efficiency and cost savings.
 Large data sets rendered to virtually any AutoCAD or GIS format provides easily understandable graphical representations of otherwise quite an overwhelming volumes of data.

 Instrument primarily used for quick surveys not extensive data collection
 Users like an analog display rather than digital
 Ergonomic improvements were not considered important
 Went through several variations on handles, but users liked old style
 Durability is important.
 Familiar packaging styles was preferred
 Calibrations important
 Reliable battery power important
 Weight reduction is a good goal

 Older generation instruments used taut-band meters that were susceptible to movement-induced needle wobble. New instruments utilize microcontroller / gear-reduced stepper motor design to eliminate the wobble while keeping the familiar look.
 Temperature and pressure sensors are used to automatically compensate the readings, alleviating the user from tedious manual corrections for atmospheric pressure.

 Consumable materials, such as the desiccant, are viewable without opening the case.
 Rechargeable batteries reduce the need to open the instrument case.
 Access within the case is easier, including a threaded chamber with no attaching cable, which allows extremely easy replacement.
 The instruments are getting lighter.

 Most important, the new generation ESI Model 20 is calibrated from a computer through the USB port .
 This allows all ranges to be calibrated quickly from a single point and reduces the exposure of the calibration technician to the calibration sources.
 User-definable settings can be set at the same time and stored in the non-volatile memory.

 ESI Model 20 provides a recognizable instrument easily useable by personnel experienced in ion chamber meters.
 However, unit is a platform for more extensive usage.
 Digital operation allows expansion of capabilities.
 Can be used for data collection.