Decade Ratio Transformer
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Decade Ratio Transformer r 7 • Resolution 0.1 ppm • Terminal linearity 0.9 ppm • Bandwidth 50 Hz to 20 kHz • Parallel switches reduce contact resistance • Switch Resistors virtually eliminate switch transients • Ratio range from -0.0111111 to +1.1111110 v__ Model DT72B is an inductive voltage divider that meets or exceeds all of the requirements for a calibration standard in precision measurement applications. It is easy to integrate into systems for calibration of voltage dividers, transformer standards, synchro/resolver standards, transformers, calibrators, ammeters, and voltmeters. It can also be used to make impedance or capacitance comparisons. The ratio accuracy is traceable to the National Institute of Standards and Technology. This variable AC voltage divider demonstrates extreme precision for measuring and generating voltage ratios. Seven decades of tapped transformer windings are selected using special low resistance switches providing 0.1 ppm resolution and 0.9 ppm terminal linearity. The key to these standards is extremely stable toroidal transformers, resulting in precision and outstanding longterm stability over a wide range of environmental conditions. The seven in-line control knobs permit quick, easy setting of the required ratios. The first dial has end stops to prevent accidental switching from zero to full output. The other dials rotate independently through 360° of rotation to simplify the settings. The switch settings are easily read from the large-numeral in-line presentation above the knobs. Switching transients are virtually eliminated due to a special circuit which couples the adjacent voltage steps through a resistor while the switching is taking place. The range overlap between decades is ±10 %, permitting accurate voltage ratios from 1.1 to -0.1. The high input impedance of the DT72B makes it well suited for use in high impedance circuits without causing excessive loading. Prices and specifications subject to change without notice.

DECADE RATIO TRANSFORMER STANDARD 10 TEGAM Way • Geneva, Ohio 44041 Phone: 440-466-6100 • Fax: 440-466-6110 • E-mail: sales@tegam.com • www.tegam.com