Abstract: A method for correlating in a digital data acquisition system the time sequence of a group of events at locations remote from the master station. The method corrects the time tags on the events record for the signal transmission time between the master and remote stations and also takes into account the turnaround time at the remote station.

Abstract: A high speed, high accuracy surface temperature measuring probe of the contact type including a thin-film platinum resistance thermometer mounted in a support assembly having a low specific heat and low conductivity with a thin pure copper end cap in thermal contact with the resistance thermometer and extending along the sidewalls of the probe for a short distance.

Abstract: A method for correlating in a digital data acquisition system the time sequence of a group of events at locations remote from the master station. The method corrects the time tags on the events record for the signal transmission time between the master and remote stations and also takes into account the turnaround time at the remote station. In addition, compensation is made for the drift of the remote clocks with reference to the master clock.

Abstract: A thin film resistance thermometer is manufactured to have a predetermined temperature coefficient of resistance while minimizing the amount of metal in the film. The process involves the production of a metal film deposit on an insulating substrate such that the film deposited has a bulk coefficient substantially higher than the desired coefficient with the film being deposited to a thickness that produces the desired coefficient.

Abstract: A humidity sensing element of the capacitance sensing type having two sets of interdigitated fingers of thin film platinum deposited on a glass substrate, all covered by a coating of water absorbing material such as cellulose acetate butyrate or a silicone rubber. The coating is of thickness such that it is substantially equal to or greater than the period of the fingers of the interdigitated electrodes.

Abstract: A method for modifying an area control error signal for controlling the generation in each area of a multiple-area interconnected electric power system using net-interchange tie-line bias control where the area control error is calculated in accordance with the equationACE=.DELTA.P.sub.t1 -10B.times..DELTA.fwhere .DELTA.P.sub.t1 is the deviation of the measured net interchange from its scheduled value, .DELTA.f is the deviation of a system frequency from its set value, and B is the frequency bias of the area. The modification involves the integration of .DELTA.P.sub.t1 to produce a signal representing a measured value of the inadvertent interchange II'.sub.t1, and integration of .DELTA.f to produce a signal representing the time deviation TD'. The time deviation is multiplied by the value 10Bf.sub.o /3600 times 1/T where B is the area frequency bias and 1/T is the control weighting factor. The product of the multiplication is subtracted from the signal II'.sub.

Abstract: A bus structure for the interconnection between a data bus capable of transferring a plurality of words and a local bus which can carry only one word. This structure includes latches for storing the plurality of words for simultaneous transfer over the data bus or for sequential transfer over the local bus as required. Control logic operates to perform the necessary control over this interconnection to effect the required operation.

Abstract: A P-I-D controller in a process control system is self tuned in response to discrete time model identification parameters which are converted to P-I-D form.Additionally, the P-I-D parameters are limited to prevent them from exceeding the controller's specified range.

Abstract: A plurality of recesses and interconnecting paths are etched into the surface of a silicon wafer. A plate of borosilicate glass carrying thin-film metal deposits in a corresponding pattern is electrostatically bonded to the silicon to form a multiple-cavity variable capacitance pressure transducer.

Abstract: A preamplifier for use primarily with a solid state line scanner for amplifying the signal output from the scanner and suppressing the noise from switching spikes featuring a cascode-connected input stage in a preamplifier having its gain stabilized by negative feedback.

Abstract: Unwanted bias is eliminated from a process control system by high pass filters which are disposed between the process and the process model.

Abstract: A portable automatic disappearing filament optical pyrometer having low power demand incorporating a solid state line scanner as a sensing element is controlled by a microprocessor to perform a balance between the radiation from a target and a lamp filament to provide a digital indication of the temperature of the target including compensation for emissivity of the target.

Abstract: A circuit for preventing data transfers to a RAM by a microprocessor when primary ac power fails also puts the RAM in standby after a period adequate to complete any data transfer started. The sequence is provided by providing a first signal to the microprocessor transfer enable line upon loss of primary power. A second signal is provided for the enable line of the RAM after a predetermined delay but before decay of the dc power to the RAM.

Abstract: A thin film resistance thermometer is manufactured to have a predetermined temperature coefficient of resistance while minimizing the amount of metal in the film. The process involves the production of a metal film deposit on an insulating substrate such that the film deposited has a bulk coefficient substantially higher than the desired coefficient with the film being deposited to a thickness that produces the desired coefficient.

Abstract: A means to change the position of a drive unit in accordance with desired changes periodically provided as a digital value and entered in a first register, which is then decremented to zero by counting actual increments of drive unit change. Power to change the drive unit is proportional to the residual value in this register, with no power when actual change has equalled desired change. The count of actual change increments is determined from clock pulses updating a second register representing position whenever the analog equivalent of this register differs from an analog signal representing actual position.

Abstract: A process for automatically identifying the parameters of a controller which controls a process and a process model which includes changing alternately the set point for the process by a predetermined value above and below the desired set point of the process which is continued until the parameters of the process model describe the process.The apparatus includes means for creating a cycle that has a plurality of steps, means for comparing a proportional amount of a set point change with a corresponding value of the process during one of the cycles steps during which the parameters are identified, means for repeating the cycle until the change in the values of the parameters between adjacent cycle is less than a predetermined amount, and means for terminating the cycle repetition if the parameter change between adjacent cycles is less than the predetermined amount.

Abstract: A signal compensating network for use with a sensing element having different rates of response for increasing or decreasing sensed quantities includes a differentiating amplifier having different time constants for increasing and decreasing input signals. The output from the differentiating amplifier is combined with a signal representing the magnitude of the input signal to produce an output.

Abstract: An analog to digital converter of the ramp-integrator type with provisions to reduce errors due to offset voltages. The cycle which is utilized includes a preconditioning cycle during which the capacitor is charged while the input to the buffer amplifier is connected to the datum level voltage, such as ground. A microprocessor is used to compute the unknown signal.

Abstract: A time variant measured variable is graphically displayed in moving strip chart format on a cathode ray tube. During a scan line the electron beam is intensity modulated at a position on the scan line whith represents the magnitude of the measured variable at a given time. The intensity of the electron beam at positions in successive scan lines is similarly intensitymodulated to produce a trend line representing the magnitude of the variable along the strip chart format. During the scanning of a subsequent raster frame, a new data value of the measured variable is displayed at a selected position at an edge of the viewing area of the strip chart format in thwe location previously occupied by the next sequential value and the older data values are simultaneously displaced. The oldest data value is deleted from the format. During a raster scan the electron beam is modulated at different intensity levels to produce chart lines and time lines on the strip chart format.

Abstract: There is provided a method for measuring a parameter whose value is calculable as an integral with time of a function of at least one variable so as to make possible the use of a microprocessor when measurements of such variables are desired. The variable is sampled periodically at a frequency asynchronous with the wave form which the variable follows and then there is periodically calculated the value of the function by summing the values for the function determined by the samples taken during the time between the calculations, thus determining the desired integral.