SR-60 Data Logger
The SR-60 is a data logger board that is available in several different configurations to meet the requirements of our customers. The SR-60 permits recording of all data gathered during a radiation survey. It may be retrofitted to existing instruments or mated with an SRA Stand-Alone Instrument Module (SIM) and a detector probe to create a complete instrument.
Most commercially available data-logging instrumentation records a single measurement when requested by the user. This single measurement is recorded when an event occurs (such as when a button is pressed or a bar code is read, etc.). During a survey, few measurements are typically recorded, most often a fixed time count. In contrast, the SR-60 records continuous data at user-defined intervals (time or distance), and is designed to permit combining the scan survey data with quantitative fixed measurements as is typically done for field measurements. This single process provides a scan with logged data, and can aide in removing human errors from the measurement process. An appropriately designed survey can now eliminate fixed time counts by using the recorded scan data.
The SR-60 is a small, low power microprocessor device that can be retrofit to any existing instrument to provide data logging capability. The power requirements for the SR-60 will not reduce the overall host instrument battery lifetime by more than ten percent. Over eight hours of data at one-half second intervals can be recorded. The most inexpensive model of the SR-60 is the SR-60-SC which consists of a small board that has a serial connector. This can then be mated with a Pocket PC and serial cable plus the SRA Virtual Instrument Module (VIM) software to form a board controller and data logging PC. The next step up is the SR-60-PD which includes an external pendant with button controls for control of the SR-60 board. The Pocket PC and VIM can be used in this configuration also. The third model of the SR-60 is the SR-60-BT which uses "Bluetooth" wireless connectivity to eliminate the need for a serial connection to the Pocket PC. Finally, the SR-60-BT-SIM uses a small Stand-alone Instrument Module (SIM) to form an entire replacement instrument with a discriminator and high voltage supply. The SR 60 VIM software allows complete control over data logging, calibration, and user interface. VIM technology allows multiple alarm set points or complete customization to site survey requirements. With the sophisticated VIM technology, procedures and instrumentation can be merged to capture bar-code data and survey data in one survey session.
Two different wheel encoder options are available: the WECM-LFM is a bolt-on solution for Ludlum floor carts to log position, and the WECM-SA is a stand-alone handheld wheel encoder for a technician to use indoors or outdoors.
There are two available Pocket PC options: 1) the SRA-PPC1 which is a HP-5555 Pocket PC or equivalent (w/ Bluetooth and Wi-Fi included), a ruggedized case, and a serial connection cable, and 2) the SRA PPC2 which is a Symbol ruggedized Pocket PC or equivalent, with built in bar-code scanner and serial cable. Client-owned Pocket PCs may be used if they meet operating system and network connectivity requirements.
Optional SRA desktop software called the Information Center i-Center is available to completely control the SR 60, and to analyze and report the data. This data is mapped in a Microsoft Excel spreadsheet in a pattern that replicates the one used to record the data, and coded to create a color map. A single technician can provide data to create a color map with thousands of gamma measurements of an acre field in less than an hour of time. Four-plots of the data and statistical analysis may also be accomplished. i Center is not required for every SR-60.
Instead of assuming the survey was preformed at a prescribed constant speed, the logged speed data shows the variability so that minimum detectable concentration (MDC) calculations may be made a postiori. Thus the a-priori MDC may then be verified and cross-checked. Presenting the data in a 2 dimensional image helps one determine the background of the survey area and to visualize if the data is spatially correlated.
