Abstract: A foam detector generally including a pair of leads positioned adjacent to a surface layer of a fluid so that foam created on a surface layer of the fluid contacts at least one lead and sends a signal to a controller connected to the leads.

Abstract: A foam detector (10) generally including a pair of leads (14, 16) positioned adjacent to a surface layer (26) of a fluid (24) so that foam created on a surface layer (26) of the fluid (24) contacts at least one lead and sends a signal to a controller (18) connected to the leads (14, 16).

Abstract: An apparatus for sequentially pyrolyzing a plurality of samples held in sample tubes comprises a substantially vertical passage through which tubes carrying the samples may be passed; an upper gas-tight valve for closing off the upper end of the passage; a lower gas-tight valve for holding a sample tube in the passage; a distribution valve directing purge gas and carrier gas to the top end of the passage and for passing pyrolyzed sample from the bottom of the passage to an analytical device; and an electrical heating element for heating the passage to temperatures at which a sample will be pyrolyzed.

Abstract: A system for maintaining back-pressure in chemical laboratory testing apparatus includes a modified flow control valve governed by a special control system which includes an input/output controller. That controller includes a microprocessor and memory into which a program developed specifically for the modified valve has been placed. A pre-pressure valve is also used upstream of the instrument in which the pressure is to be maintained for effecting quicker control of the pressure. The input/output controller, in conjunction with the servo-amplifier, integrates out the error between the desired set-point pressure and actual pressure thereby enabling maintenance of pressure within one pound.

Abstract: An electromagnetically actuatable probe is inserted in a vessel containing a body of liquid and in which high pressure, high temperature, corrosive, or other hostile conditions exist. Pulses are transmitted to the probe within a predetermined range of frequencies which include the normal resonant frequency of the probe. Return signals are generated by the probe between the times the transmitted pulses are sent. These return pulses are processed to produce signals which are a function of the level of the liquid that are then employed to control the discharge of the liquid or used by another utilization circuit.

Abstract: A reactor tube of a microreactor assembly including a first central temperature sensor and a channel formed in its outer surface to circulate a coolant. A tightly fitting conductive core surrounds the cooling channel and is sealed to the reactor tube at both ends to confine the coolant except for inlet and outlet holes. Around that core a metallic tube is fitted having a longitudinal slot to which a second temperature sensor is fixed. A heating element to heat the tube and the reactor tube is disposed on the slotted tube and second sensor so that temperature changes on the outer wall of the reactor tube-core sub-assembly can be detected. Both the first and second temperature sensors are adapted to feed output signals to a controlling data processing unit.