Using this instrument, you need not bend down, nor attach many connections. Using CP Voltmeter, Errors in measurement are reduced drastically because of specially made voltmeter for CP Survey. Powered by 9 Volt Battery requires no push to read switch, and the solid-state integrated circuit has built-in filter to reject AC interference. Input resistance of 10 megohms (10 million ohms) of this instrument results in potentiometer quality voltage readings. The instrument measures direct reading in mV when connected with half-cell.