UPM-DT-1 & 10

UPM-DT Series 1 & 10 Wattmeters verified by NIST & FDA
Models UPM-DT-1 & 10 are precision wattmeters designed to measure the power output of diagnostic and therapeutic ultrasound transducers. The UPM-DT series have been in use worldwide since 1977 and conform to the testing guidelines recommended by FDA, JCAHO, AAMI and AIUM. Since the power is measured by a primary method, the accuracy of the UPM-DTs is traceable to NIST.

UPM-DT-1 & 10 FEATURES

UPM-DT-100

Portable standard for therapeutic transducers
UPM-DT-100 is a compact microprocessor-based ultrasound power meter for testing therapeutic applicator heads for safe radiation levels.

UPM-DT-100 FEATURES

Principle of Operation
The most reliable and repeatable means of measuring ultrasound power is the radiation force method. The transducer to be tested is centered above a 45° air-backed cone target in water media, which is linked to a precision balance capable or resolving 0.1mg. When acoustic energy is applied to the cone, the resultant force exerted on the load cell of the balance is directly proportional to the total radiated power. The test tank is lined with sonic absorbent rubber to prevent power reflection. The balance is programmed to convert milligram magnitude forces directly to a readout in watts with resolution to the nearest 0.002 watt for Model UPM-DT-1 and 0.01 watt for Model UPM-DT-10. Verification of the UPM-DT Series is easily accomplished by placing a calibrated weight on the arm of the target cone. (A 10 gram weight is equal to 14.65 watts).

Model UPM-DT-100 weighs only seven pounds and is easy to set up. To operate, only two controls are required. OFF/ MODE: Turns power off, selects grams or watts display and controls the optional RS232 printout. ON/TARE: Turns power on and resets the unit to zero prior to taking the measurement. On battery operation, the unit can be used Òon-siteÓ for approximately 50 hours. In addition, Model UPM-DT-100 is easily converted to a top-loading balance with 600 gram capacity and 0.1 gram resolution.

The Importance of Calibrating Ultrasound Transducers
It is important to measure ultrasound power levels to determine exact patient exposure and minimize potential risks. All diagnostic and therapeutic Doppler and ultrasound equipment should be tested periodically. Typical safe values are defined by the temporal average intensity at the point in the acoustic field where the intensity is at its maximum value, referred to as Spatial Peak Temporal Average (SPTA). The FDA and AIUM provide guidelines for the maximum SPTA values in medical applications. Typical safe SPTA values are 10mW/cm² for echo sounding. 100 mw/cm² for Doppler devices and 3W/cm² for therapeutic use. The watt density (watts/cm²) of a transducer is determined by measuring the total power output and dividing by the active cross sectional area of the transducer. A sample form to document and report ultrasound performance is included in the manual.

Testing accuracy of ultrasound therapy equipment
The Model UPM-DT-100, Ultrasound Power Meter, was developed to test therapeutic transducers according to AIUM, JCAHO, FDA and NIST guidelines. OHMICÕs ultrasound wattmeters have been used worldwide since 1977 and are the most widely accepted standard for documenting the power output of medical transducers.

The performance of the UPM-DT Series has been tested and verified to be within the limits of tolerance by the Food & Drug Administration (FDA) and National Institute of Standard & Technology (NIST). Model UPM-DT-100 meets all the requirements of a portable test instrument with the reliability and proven performance of the UPM-DT Series. The DT-100 unit uses the identical test tank and target configuration as the high resolution UPM-DT-1 and UPM-DT-10 Series.