Abstract: Apparatus, assembly and method for investigating the integrity of a seal and sealant contained in a sealing fitting used in hazardous locations. The apparatus/assembly can include signal transmitters and signal receivers provided on a conduit system on either side of a sealing fitting. The apparatus/assembly can include probes placed on either side of a sealant within a sealing fitting, the probes placed in probe ports provided through the wall of the sealing fitting.

Abstract: A furnace controller circuit includes a microprocessor with input ports and output ports including ports to issue control signals for actuation of inducer, gas burner, and furnace blower. A temperature-actuated limit switch commences a furnace shut-down sequence when the temperature of the furnace heat exchanger exceeds a predetermined limit temperature, and then resets to permit a turn-on sequence. An LED visible fault indicator is coupled to the microprocessor to provide visible fault messages. A non-volatile memory device coupled with the microprocessor is operative to store fault indications when present. In the event of power restoration after power failure, the limit switch status and other fault status are maintained. A lockout period is computed based on length of furnace run time until fault and recent fault history. Limit switch and other safety faults are recorded and these can be weighted and ranked based on age of each fault occurrence.

Abstract: A user interface of a controller has multiple touch-sensitive input transducers, e.g., capacitive pads. The pads are dynamically indicated: When any given touch sensitive input device is needed for input at a given step of the programming operation, an associated light source illuminates that input device so it is visible to the user. Those touch-panel input devices not needed for that are left unilluminated, and the microprocessor ignores any input from those input devices. At each step of the operation or programming of the controller, only those input transducers for the inputs that are permitted or relevant to that state are indicated. Correspondingly, only the inputs that are generated by actuating the input transducers for the valid (i.e., permitted or relevant) inputs results in a change in the state of the program in the microprocessor.

Abstract: A user interface of a controller has multiple touch-sensitive input transducers, e.g., capacitive pads. The pads are dynamically indicated: When any given touch sensitive input device is needed for input at a given step of the programming operation, an associated light source illuminates that input device so it is visible to the user. Those touch-panel input devices not needed for that are left unilluminated, and the microprocessor ignores any input from those input devices. At each step of the operation or programming of the controller, only those input transducers for the inputs that are permitted or relevant to that state are indicated. Correspondingly, only the inputs that are generated by actuating the input transducers for the valid (i.e., permitted or relevant) inputs results in a change in the state of the program in the microprocessor.

Abstract: A furnace controller circuit includes a microprocessor with input ports and output ports including ports to issue control signals for actuation of inducer, gas burner, and furnace blower. A temperature-actuated limit switch commences a furnace shut-down sequence when the temperature of the furnace heat exchanger exceeds a predetermined limit temperature, and then resets to permit a turn-on sequence. An LED visible fault indicator is coupled to the microprocessor to provide visible fault messages. A non-volatile memory device coupled with the microprocessor is operative to store fault indications when present. In the event of power restoration after power failure, the limit switch status and other fault status are maintained. A lockout period is computed based on length of furnace run time until fault and recent fault history. Limit switch and other safety faults are recorded and these can be weighted and ranked based on age of each fault occurrence.