Water-Flow Safety Switch for Gas or Electric Heaters

Abstract

difference between the setting of the Rubicon Type B potentiometer and the e.m.f. of a Chromel-Alumel furnace thermocouple. The recorder is equipped with a cam, relay, and resistors so that it controls the temperature that it measures.By this arrangement-essentially zero suppression-it is possible to record temperature over a wide range without loss of sensitivity. It was found that room temperature changes overnight were sufficient to change the potentiometer working battery voltage by more than 1 mv., or the opposition voltage by more than 12 µ . (equivalent to a temperature change in the furnace of about 0.3°C.