Twintech control systems offers a digital tachometer with lcd display. Leading industrial houses such as cummins india and many other small-scale industrial units uses these. Salient features: supply: 24 v dc; input - sine wave frequency of amplitude 2.0 to 30 v rms; maximum count - 19,999 rpm; accuracy - ± 1 rpm; cost effective features - protection from reverse polarity supply 24 v dc, withstands vibrations of diesel engine panels and ambient temperature 70° c.