Abstract: A method for evaluating the type, extent, and threshold of fouling in a heat exchanger test tube by using a reference test block to measure a reference thermal relaxation time at a guaranteed clean reference section of a heat exchanger test tube and comparing the reference thermal relaxation time with thermal relaxation times measured at the bottom region of unclean sections of the heat exchanger test tube.

Abstract: A method of and a system for monitoring circulating water systems for conditions susceptible to deposition of a variety of scaling deposits. The invention includes presenting upset conditions at a surface area in the circulating water stream, or in a sidestream in a conduit connected to the main circulating water system, and closely monitoring either heat transfer rate or heat transfer resistance at the water contact surface adjacent the area of upset. When conditions for scaling are present, the upset conditions tend to cause formation of scale deposits at the upset area before the scaling occurs in the main circulating water stream, permitting countermeasures to be taken which inhibit scaling. In the specific case of boilers, heat exchangers or cooling towers, CaCO.sub.3 scaling is monitored at an area where the upset conditions are present, the upset conditions are an increase in the heat transfer rate. The solubility of CaCO.sub.

Abstract: This invention is a method for evaluating the type, extent, and threshold of fouling in a heat exchanger test tube by using a reference test block to measure a reference thermal relaxation time at a guaranteed clean reference section of a heat exchanger test tube and comparing the reference thermal relaxation time with thermal relaxation times measured at unclean sections of the heat exchanger test tube.

Abstract: A monitor for measuring heat transfer resistance comprising a housing and one or more test block assemblies, each test block assembly includes a movable test block enclosed on two sides by parallel side supports and attached by a spring to a spring support. Each test block assembly is attached to the housing. The spring urges the movable test block away from the spring support. Additionally, the movable test block will contain a heater, a thermometer, or both the heater and a thermometer.

Abstract: A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively.