The Advanced Therapy Dosimeter, Model 35040, is a reference grade instrument with superior performance in either its basic configuration or customized to user preferences. The Advanced Therapy Dosimeter exceeds the recommendations of calibration laboratories for leakage, linearity, and stability by a wide margin. The long-term stability error is designed to be less than 0.1% over five years. Non-linearity error is much less than recommended by calibration laboratories, and system current offset error is virtually nonexistent for practical measurements. The Advanced Therapy Dosimeter satisfies fundamental user requirements and provides the flexibility to customize displays and perform automatic calculations. While significantly raising the standard of measurement, the Advanced Therapy Dosimeter provides useful information that is not available from other dosimeters.
The Advanced Therapy Dosimeter is used in calibration dosimetry, quality assurance, and diagnostic testing of linear accelerators. A unique electrometer design provides more accurate dose and dose rate measurements than conventional high meg resistor or capacitor feedback electrometers. The flexibility of the Advanced Therapy Dosimeter optimizes user efficiency and saves time. The Advanced Therapy Dosimeter is fully stable within five minutes, a fraction of the time of conventional dosimeters. Front panel controls select ion chamber calibration factors, enable air density correction, facilitate temperature and pressure entry, and allow bias voltage selection and display. The Advanced Therapy Dosimeter measures effective exposure time in a single exposure, thus eliminating the need for multiple exposures for Cobalt 60 and brachytherapy measurements.
User-customized and front-panel selectable display screens can simultaneously and in real time show dose, dose rate, effective exposure time, average current/rate, accumulated charge/dose, bias voltage, leakage, and other important information that ensures the validity of the measurement.
The Advanced Therapy Dosimeter's customization software allows the user to design up to 16 display screens that display internal conditions, set-up parameters, measurement values, and text information. The software allows the user to enter up to 32 ion chamber calibration factors. Users can program up to 11 bias voltages in 1/10-volt increments from -500 volts to +500 volts in any sequence and select the values from the front panel. The customization software operates with an IBM-compatible PC and connects via a RS-232 cable.
