Scientech Technologies Pvt. Ltd. Manufactures 3 & 1/2 Digits Multimeter with TTL Logic, Square Waveform Output and Frequency Measurement, Caddo 51. Scientech Technologies Pvt. Ltd. Is an ISO 9001:2000 certified company. The 3 & 1/2 Digits Multimeter with TTL Logic, Square Waveform output and Frequency Measurement are used for diode, continuity, transistor, TTL logic and frequency testing. Salient features of this Multimeter are as follows: