Mercury coulometer

Abstract: A coulometer signaling device is disclosed which indicates when a particular machine has been used for a predetermined amount of time. The device comprises a mercury coulometer which includes an electrolyte whose color changes when the mercury deposited on the anode of the coulometer has been depleted. The end of the tube near the coulometer is somewhat enlarged and a lens is placed over this end in order to make the color change more visible.

Abstract: It is possible to directly measure average temperature with a simple electronic circuit and avoid the usual time—consuming arithmetic integration of temperature records. Instructions are given for the construction of an electronic integrating thermometer composed of a thermistor in a simple Wheatstone bridge and a mercury coulometer that provides a direct readout of the average temperature of soil, air, or water over a designated time interval. See full-text article at JSTOR

Abstract: 57 In a calibration warning device for a thermocouple, the thermocouple is connected to input terminals (10) of an operational amplifier (12) provided with negative feedback. The output is applied to the base of a transistor (14) controlling the current through a mercury coulometer (18). When the coulometer indicator reaches full-scale deflection the thermocouple is due to be recalibrated. The invention depends on the fact that the drift curve of a thermocouple can be matched to a sufficiently high accuracy by a suitable choice of transistor characteristic and amplifier gain, as is explained in the specification.

Abstract: PURPOSE:To permit checking of the consuming condition of a corrosion preventive bar from the outside in a galvanic anode system by providing an electrolytic coulometer which electrically connects the corrosion preventive bar and can body wall to the outside of the can body. CONSTITUTION:The corrosion preventive bar 2 which is a sacrificial anode is inserted into the can body 1 made of a metal. A mercury coulometer 5 as the electrolytic coulometer and a shunt resistor 7 are disposed to the outside of the can body 1 and are connected by conductors 6 to the corrosion preventive bar 2 and the can body wall. The ratio Ia/Ir of the shunt current is then adjusted by the shunt resistor 7 until the service time T to the loss of the corrosion preventive effect on progression of the consumption of the corrosion preventive bar 2 coincides with the scale 100% indicating the extent of the movement of an electrolyte 53 by the dissolution and depositing of mercury 54 of the mercury coulometer 5. Liquid is stored in the can body 1 constituted in the above-mentioned manner. Corrosion preventive current I is shunted by the shunt resistor 7 and the current Ia flows to the coulometer 5 when galvanic action is generated between the bar and the can body wall. The electrolyte 53 of the coulometer 5 is thereby moved. The scale 100 indicating the extent of the movement is attained when the corrosion preventive effect is lost on progressing of the corrosion of the bar 2.

Abstract: The results of studies on mercury capillary coulometers containing acidified electrolyte solutions (fluoroborate or perchlorate) or neutral solutions are presented. The effects of the solution composition on the coulometer properties such as internal resistance, current yield, and electrochemical stability are discussed. It has been shown that the solutions of mercury salts which contain fluoroboric or perchloric acid are more advantageous for use as mercury coulometer electrolytes than the iodide solutions used hitherto.