N2304

The N2304 is a switching and balancing device for transducer bridges, for static multipoint measurements together with the N2301, made by IEMI in Bucharest and designed at the ICE research institute in Bucharest [1]. It was exported to East Germany in 1971–1974 [1].

ICE’s laboratory for electronic instruments for measuring non-electrical quantities designed approved prototypes for many branches of the economy: strain gauge equipment (some configurations were exported to East Germany in 1971–1974 and 1977–1989), vibration meters, dimensional gauges, ultrasonic non-destructive testers, geophysical well-logging equipment and railway equipment [1]. Its designs were made in series at IEMI (27 types) and at the Precision Mechanics Enterprise (5 types), or in ICE’s microproduction workshop (45 types) for small series and one-off models [1].

IEMI’s production table lists 375 units made in 1974–1979 [2].

The memoirs of an IEMI engineer, who gives the codes as N-2102 and N-2104, say that in 1972–1974 he made the zero series of the six-channel strain gauge and of the switching and balancing device for their approval; both were meant for export to East Germany [3].

Annex III.2.12 says it connected six groups of transducers placed at different points to a single strain gauge instrument in turn, quickly, so that many instruments were not needed; it took transducers of 60–100 Ω (as printed) in bridges of two or four transducers, with resistive balancing of ±2% and capacitive balancing of 0–800 pF [4].