Abstract: A stirring hot plate for simultaneously heating and stirring a mixture includes a phase controlled motor that spins magnets which couple to, and thereby spin, a stir bar within the mixture. In addition to spinning the magnets, the motor includes an operational mode in which the motor is rapidly braked thereby quickly spinning down the stir bar. The stirring hot plate also includes a visual indicator to the user that the platform is hot-to-the-touch that is especially effective when the stirring hot plate is not in use.

Abstract: A stirring hot plate for simultaneously heating and stirring a mixture includes a phase controlled motor that spins magnets which couple to, and thereby spin, a stir bar within the mixture. In addition to spinning the magnets, the motor includes an operational mode in which the motor is rapidly braked thereby quickly spinning down the stir bar. The stirring hot plate also includes a visual indicator to the user that the platform is hot-to-the-touch that is especially effective when the stirring hot plate is not in use.

Abstract: A method of determining liquid absorption of an aggregate comprises providing a sample of the aggregate, adding liquid to the sample, subjecting the sample to a light source signal, monitoring a light reflected signal reflected from the sample and controlling addition of liquid to the sample as a function of the light reflected signal. The apparatus comprises a support for supporting a sample of the aggregate, a liquid source for adding liquid to the sample, a light source which subjects the sample to a light source signal, a light sensor which senses a reflected light signal reflected from the sample and a processor/controller which controls addition of liquid from the liquid source as a function of the reflected light signal. The light source is preferably an infrared source and the light sensor is preferably an infrared detector.

Abstract: A method of determining liquid absorption of an aggregate comprises providing a sample of the aggregate, adding liquid to the sample, subjecting the sample to a light source signal, monitoring a light reflected signal reflected from the sample and controlling addition of liquid to the sample as a function of the light reflected signal. The apparatus comprises a support for supporting a sample of the aggregate, a liquid source for adding liquid to the sample, a light source which subjects the sample to a light source signal, a light sensor which senses a reflected light signal reflected from the sample and a processor/controller which controls addition of liquid from the liquid source as a function of the reflected light signal. The light source is preferably an infrared source and the light sensor is preferably an infrared detector.

Abstract: A furnace having an easily disassembled vacuum chamber to facilitate muffle replacement. The muffle is located over pins on the vacuum chamber base and is held against the base by a leaf spring between the muffle and the vacuum chamber top. The cylindrical wall of the vacuum chamber is correctly located with respect to the muffle by upright spacer bars upstanding from the vacuum chamber base about the periphery of the cylindrical wall. The spacer bars further serve to tie the top and base of the vacuum chamber together and against the cylindrical wall. The furnace is bottom loaded and has a door seal carried by the base so that the seal is not exposed to the direct heat from the muffle when the door is opened.