Advanced Therapy Dosimeter
Model 35040 Electrometer
The Model 35040 Advanced Therapy Dosimeter is a reference grade
instrument used to measure the charge and current from ion chambers in Radiation Therapy, and provides bias
voltage for all commonly used chambers. The ATD large clear display offers direct readings of charge, current,
time and radiation units over a wide range. The user can customize the display for basic use or for specialized
applications such as brachytherapy.
Model 35040 Advanced Therapy Dosimeter exceeds the recommendations of
calibration laboratories for leakage, linearity, and stability by a wide margin. This instrument raises the
standard of Radiation Therapy measurements.
The Model 35040 Advanced Therapy Dosimeter provides the long-term
stability and accuracy demanded for calibrations, quality assurance programs, and protocols in Radiation Therapy.
Radiation Therapy requires great accuracy in the measurement of dose and dose rate values associated with
linear accelerators and radioactive sources. The Model 35040 Advanced Therapy Dosimeter
provides the long-term stability and accuracy demanded for calibrations, quality assurance programs,
and protocols in Radiation Therapy. A unique electrometer design provides more accuracy than high meg resistor
or capacitor feedback electrometers.
The Model 35040 Advanced Therapy Dosimeter is fully stable within
five minutes. In battery operation or using AC Line, the ATD measures dose and effective exposure time in a
single exposure, thus eliminating the need for multiple exposures for Cobalt 60 and brachytherapy measurements.
Front panel controls select ion chamber calibration factors, facilitate entry of temperature
and pressure values for air density correction, allow bias voltage selection,
threshold level, timer control, and choice of display
screens. The user-customized display screens can simultaneously show
dose, exposure time, dose rate, effective
exposure time, average current/rate, accumulated charge/dose, bias voltage,
leakage, and other important
information that ensures the validity of the instrument.
The customization software allows design of 16 screens that display conditions,
parameters, values and text. Up to 32 chambers factors, 11 bias voltages can be programmed.
It is PC compatible and connects via a RS-232 cable.
- Now with timer function and wider dynamic range
- Ultra long-term stability error of approximately 0.1% per five years.
- Virtually removes effects of system leakage during measurement.
Uncorrected leakage < 10 fA over temperature range
- Eleven user-defined bias settings from -500 V to +500 V
- Read out in C, A, R, Gy, Sv, Bq, and more
- Wide measurement range, up to 1.000 µA and 19.999 mC for HDR Brachytherapy applications
- Automatic reset and hold of measured valued between exposures
- Front panel adjustment of exposure threshold and user disable of threshold to permit manual operation
- Thirty-two ion chamber calibration factors
- Automatic power-down after user-specified time period, when operating from battery supply
- Annunciators warn of low battery, low bias, and operational errors
- Large capacity battery provides eight hours of continuous operation;
fast recharge in less than three hours, even during operation
- AC line operation over the range 100 to 240 VAC and 47 to 63 Hz without operator intervention
- Charge and current calibration factors entered by calibration laboratories at user's option
- Front and rear panel ion chamber connections
- Optional carrying case (Model 37780)
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