Two Probe Method for Resistivity Measurement of Insulators at Different Temperatures - BRAND - VIJAYANTA, INDIA 1. Two Probe Method for Resistivity Measurement of Insulators at Different Temperatures, TPX 01 The Apparatus consists of the following Sub. Unit : (a) Two Probe Arrangements with built in RTD sensor, TPA TPX 01 (b) PID Controlled Oven, PID 200 (c) High Voltage Power Supply, EHT 11 (d) Digital Picoammeter, DPM 111 Complete in all respect.