What is an E-meter?
The E-meter, or eletro-psychometer, is based on a Wheatstone bridge circuit, and measures differences in the subjects skin resistance in a crude fashion reminiscent of a lie detector. Circuit details and method of operation are posted regularly to a.r.s. and can be found on some of the critical Web pages. Physically, it is very 1950s art deco in appearance, with a large analog meter as the prominent feature. Several knobs give the operator control over the sensitivity and range. The subject (or Pre-Clear) grasps two empty common soup cans (one in each hand) which are used as terminals. (Footplates were tried but were rejected as unsuitable.) Thus, being “..on the cans” is slang for being audited. According to Hubbard, any positive change in skin resistance noted by the E-meter is the result of the presence of the `mental mass’ of an engram. Thus, engrams can be detected. Likewise, a gross absence of resistance is taken as meaning an engram (or its charge) has been dissipated (or `flatt
