Pioneering Work

First or Among the First to Introduce:

General Radio founded in 1915
1918Decade Bridge
1920Variable Air Condenser
1923Invented the Binding Post
1923Direct Reading Wavemeter
1926String Oscillograph
1927Direct Reading Ohmmeter
1928Vacuum Tube Bridge
1929Output Meter
1930Decade Resistor
1930Decade Condenser
1930Piezo Electric Oscillator
1931Frequency Meter
1931Vacuum-Tuber Voltmeter
1933Impedance Bridge
1933Volume Control
1935Variable Inductor
1937Sound Level Meter
1937Voltage Divider
1932Edgerton Stroboscope
1940Broadcast Frequency Monitor
1956dc Amplifier and Electrometer
1956TV Transmitter Monitor
1961Tuned Amplifier and Null Detector
1976Modern LCR Meter "Digibridge"
and much more…Improvements on these and other products continued in the years that followed…

esi founded in 1944
1960-1970’sSR-104 0.5 ppm Resistance Standard
1960-1970’sRS925 First 20 ppm Resistance Decade Box
1960-1970’s242D First 10 ppm Resistance Measurement System

IET Labs founded in 1975
1975RS/CS/LS Series Thumbwheel R-L-C Decade Substituters
1977DM-45 First Pocket Autoranging DMM
1979CM-500 Capacitance Meter
1980-1990’s-PZS-First Programmable R-L-C Decades
1980-1990’s-SRL-High Accuracy Resistance Standards from 1 mΩ - 10 TΩ
1980-1990’s-HRRS-High Resistance, High Voltage Resistance Decades
1980-1990’s-KVD-High Performance Kelvin-Varley Voltage Dividers
2000IET Acquires GenRad Classic Product Line
2002Expanded the 1482 inductance series from 1 uH - 100 T
2004Released Capacitance Standards as high as 10,000 µF
2006IET Acquires GenRad Megohmmeters and Digibridges
2006IET Acquires esi Resistance Line
2009SR103; 0.5 ppm stability resistance standards at 1 kΩ
2010The 1865+ Megohmmeter
20111404 10 nF Capacitance Standard
2011Upgraded the Digibridge IEEE Board
2013HPRS-Hipot-Load High Power Resistive Load
2014Redesign of LOM-510A Milliohmmeter
2016Released PRS-300 Programmable Decade Resistor
2018Redesign of 1986 Omnical Sound Level Calibrator
2019Released SRAC ac Standard Resistors
2019Released PRS-330 Programmable Decade Resistor
2019Released PRS-370 Self-Adjusting Programmable Resistance Decade Substituter