Microammeter `` M-91 ''.
Instruments for adjusting and controlling the PTA.The microammeter "M-91" has been produced by the Leningrad plant "Vibrator" since 1949. The device is made on the basis of the M-91 galvanometer and differs from it only in the limits of measurements and the parameters of the measuring mechanism (the opposing moment of the stretch marks and, possibly, the winding data of the frame). The microammeter was released to the measurement limits: 0 - 1; 0 - 3; 0 - 10; 0 - 30; 0 - 100 μA. Accuracy class 1.0. Operating temperature range from +10 to + 350C. The change in the readings of the device from the temperature deviation from the normal (+ 200C) does not exceed - / + 0.5% of the upper limit of the scale for every 10 degrees. The counteracting moment of the stretch marks on the device is 0-10 μA ... 0.4 mg * cm / 900 for a length of 100 mm. There was a version of the device that was different from the one shown in the photo - it supplied the power to the illuminator light not through the plug in the upper end of the case (not shown in the photo), but through a cord with a plug mounted directly into the power supply switch on the front panel. The price of the device is 540 rubles (according to the 1954 price list).
