A randomness monitor designed to check when the duty cycle of a train of pulses is other than 50 percent; and to check the frequency with which a predetermined combination of digits occurs in the pulse train wherein each of the two above-mentioned function checkers includes a gating circuit, two integrators, voltage comparator and an indicator.

In a telephone monitoring means for connection between a service line and a telephone instrument, said telephone instrument including a cradle and a handset having a microphone: an energizing means, and means for simultaneously disconnecting said microphone from said service line and for connecting said microphone to said energizing means while said handset is on said cradle, so that crosstalk and line noise present in said service line are not transmitted to said microphone during monitoring.

The temperature of an advancing wire that, because of its low emissivity, could not be measured accurately by a radiation pyrometer is measured indirectly by sensing the radiation from a high emissivity sheave which is heated by the wire conductively.

In the desalter operation of a petroleum refinery, a method which measures and regulates the stability of the oil-in-water emulsion. A device located downstream of the desalter monitors the electrical charge of oil droplets in the effluent brine. This charge reflects emulsion stability. The amount of charge streaming past a point defines a current. When a predetermined streaming current threshold is crossed, the monitoring device electrically sends a signal proportional to the excess to a meteri...

An improved quadraphonic headphone arrangement in which a first audio signal is coupled to a speaker in each headphone and a second audio signal, usually monaural, is coupled to an amplifier and then to a second speaker in each headphone. Switching means are also provided so that the second speakers may be connected directly to the second audio source without amplification. The headphone is used as a musician's practice aid or for track-making or similar purposes. A prerecorded signal is coupled...

A voltage monitor is disclosed. The voltage monitor comprises a digital voltmeter for displaying a measured input voltage, and means for converting the varying input voltage of the monitor into a stabilized power supply voltage for the operation of the digital voltmeter. The input voltage is applied to the digital voltmeter through a response time controller providing a long time constant averaging value of input voltage to the digital voltmeter when the input voltage is within a predetermined r...

An A. C. current monitor for the protection of such devices as appliances and machine tools with a high Q transformer whose primary winding is series connected to the load line being monitored. The transformer is coupled to an audible alarm by a half wave rectifier filter and a solid state bilateral switch. By suitable choice of RC constant of the filter, a "chirping" response is obtained for load line currents marginally above a predetermined value in order to indicate the amount of overcurrent...

A fluid monitor for determining the percent composition of a fluid mixture of unknown composition when compared to a reference fluid mixture of known composition.

An apparatus for detecting the quantity of moisture in a given region includes a crystal of sodium chloride, a support for the crystal in the region and means for detecting the change in the electrical resistance of the crystal caused by the exposure of the crystal to moisture. A dry gas is caused to flow intermittently over the crystal to remove the accumulated moisture from it. This prevents the crystal from dissolving and allows the use of a smaller crystal than would otherwise be possible.

A monitor stand includes an upper support member (100) for supporting a monitor thereon, and a lower support member (200). The lower support member comprises a fixed piece (270), a slidable piece (210) slidably attached to the fixed piece for supporting a notebook computer connected to the monitor, the slidable piece being slidable in a first direction, a clutch (243) movable between the fixed piece and the slidable piece in a second direction generally perpendicular to the first direction to se...