Abstract: In a temperature measurement system using a thermocouple connected to a pair of circuit wires coupled to a voltmeter for providing an output reading, an isothermal block (48) formed of alumina ceramic contains a series of openings (58-66) in linear juxtaposition. Metal connectors (68) located in two of the openings to interconnect the thermocouple and printed circuit wires of a circuit board (52) establish a reference junction. A temperature sensor (50), preferably a transistor, in a third opening measures the temperature of the isothermal block (48) to compensate the output reading for error created by the reference junction. The connectors (68) are in resilient contact with the interior wall of the isothermal block (48) to maintain good heat conductivity between the connectors and the temperature sensor (50). Portions of the connectors (68) extending outside the isothermal block (48) retain the isothermal block (48) to the circuit board (52).

Abstract: A measuring system has a pair of sensors with the response time of one sensor lagging the response time of the other. The output of each sensor is sampled periodically and the outputs for two successive samples are compared to calculate the actual value of the parameters based upon the change in the two outputs.

Abstract: A temperature probe using a first thermocouple junction at the end of a metal tip for measuring the temperature of an object is also provided with a second thermocouple junction on the metal tip at a predetermined distance from the first thermocouple for detecting heat flow in the tip from the first thermocouple toward the second thermocouple. Electronics responsive to both themocouples drive a heater which maintains the second thermocouple at substantially the same temperature as the first thermocouple, thereby to eliminate heat loading by the probe on the object being measured. A single adjustable resistance temperature detector electronically connected in series with the metal tip is used to calibrate the probe and compensate for errors in the temperature readings of the first and second thermocouples. The resistance temperature detector is made up of a wire located in the handle of the probe and is adjusted by stretching the wire to reduce its diameter and bulk resistance.

Abstract: A compensation circuit for a heater wire and a temperature sensor, the temperature sensor generating a signal whose amplitude is dependent upon the amplitude of the voltage across the heater wire. The circuit comprises a comparator circuit and a priority encoder circuit for generating digital information that is a function of the amplitude of the voltage in the heater wire; a multiplexor/demultiplexor circuit, responsive to the digital information generated, for generating a reversal error compensation signal, the generated reversal error compensation signal having an amplitude that is a function of the Peltier and Thomson effects associated with the heater wire; and amplifier/chopper circuits adapted to generate a compensated sensor signal that is a function of the reversal error compensation signal and the uncompensated sensor signal.

Abstract: Apparatus for making a transition from leads (12-26) of a temperature measuring thermocouple to extension wires (44-58) within a hermetically sealed cable sheath (60) of small diameter. The interior of the cable sheath (60) is shielded from electromagnetic radiation by an electrically conductive liner (62). A thermally conductive, electrically insulating material (66) surrounds the intermediate junctions (28-42). The temperature of the intermediate junctions (28-42) is measured (64) providing a signal to compensate the voltage generated by the temperature measuring thermocouples due to the thermoelectric effect of the intermediate junctions (28-42).

Abstract: A cold junction compensation bridge for a thermocouple circuit includes a temperature compensation resistor encased in a heat conductive material and is directly connected to the same terminal block or strip to which the thermocouple leads are attached. The compensation resistor is in the same chamber of a housing as the cold junction of the thermocouple so it is subjected to the same temperature as the thermocouple junction. This is of particular importance in two wire current transmitters wherein the housings are multi compartment, with the electronics in one compartment (that may be sealed and not normally opened) and the terminal blocks for connecting the thermocouple and the like, as well as the calibrating screws, in a separate compartment. In such arrangements the thermocouple cold junction can be at a different temperature than the rest of the electronics.

Abstract: A temperature measuring device according to the present invention includes a temperature sensor which is arranged in the vicinity of reference contacts to detect the variations in temperature of the reference contacts, and a processing circuit which outputs a signal corresponding to the temperature at the measuring point by compensating the temperature at the reference contacts based on the output signal from a thermocouple and the output signal from the temperature sensor. The reference contacts and the temperature sensor connected to the processing circuit by transmission lead wires, respectively.

Abstract: An improved system for precisely measuring temperatures at remote locations using a microprocessor and resistance temperature detectors is achieved by providing means for pre-selecting a particular temperature range and using this temperature range information to generate a comparison level for determining the measured temperature. By employing the present invention, the fixed number of bits used to produce the temperature information output is concentrated over a limited range of temperatures, thereby achieving greater precision, since each information bit represents a much smaller number.

Abstract: A thermocouple type electronic thermometer which includes automatic adjustment of the signal conditioning circuitry to be compatible with the calibration curve of the thermocouple in use. A plurality of thermocouples are stored in a container which has conductive markings imprinted thereon which are a representation of the voltage/temperature characteristic of the thermocouples in the container. The markings are detected by contacts in the thermometer case, and the calibration of the instrument is altered so that the display will be an accurate indication of the temperature being measured. The principle is applicable to the measurement of other physical phenomena. The instrument is automatically switched on when a thermocouple probe is connected, and switched off when the probe is disconnected.

Abstract: A bandgap voltage reference and temperature sensor is used to determine accurately the temperature of the cold junction of a thermocouple for algebraic combination with the thermocouple signal to provide precision temperature measurements with thermocouple speed. In a discrete component embodiment copper slugs function as thermal inertial elements to equalize the thermal response rates of the temperature sensor and thermocouple. In an IC embodiment the cold junction is located on the chip in close proximity to the temperature sensor component in the chip thereby avoiding any thermal differential between cold junction and sensor.

Abstract: A method for simultaneous compensation of a plurality of thermocouple signals where the thermocouple leads are terminated to dissimilar metals without using individual ice junctions for compensation of each thermocouple signal is disclosed. The thermocouple leads are all terminated to individual connectors as reference junctions which are held at the same temperature by a block of metal which stabilizes thermally with its environment. The temperature of the metal block is measured by an integrated circuit temperature transducer which produces an analog electrical signal proportional to the temperature detected. This signal is digitized and a microprocessor calculates the temperature of the metal block which is placed on a first data bus. Additional microprocessors are connected to the individual thermocouple leads. These microprocessors convert the thermocouple signals into an uncorrected digital temperature.

Abstract: An integrated-circuit thermocouple signal conditioner having on a single chip an amplifier and a transistor circuit responsive to the chip temperature for developing a cold-junction compensation signal referred to 0.degree. Celsius. The amplifier includes two matched differential input amplifiers the outputs of which are summed and used to control a high-gain main amplifier. Thermocouple signals are applied to one of the input amplifiers, serving as a floating input stage, and the main amplifier output is connected through a feedback network to the input of the other differential amplifier. A cold junction compensation signal also is applied to the input of the other differential amplifier. The compensation is a differential voltage proportional to the Celsius temperature of the chip; the compensation voltage comprises two components having positive and negative temperature coefficients.

Abstract: An electronic human body temperture indicator comprising a thermocouple, the hot junction of which is housed within a tube through which the patient's breath is exhaled. The cold junction is positioned in contact with the ambient air, and an adjacent ambient temperature air sensor is provided. An appropriate electronic package processes thermocouple and air temperature sensor output to provide a display of the patient's peak breath temperature. A breath outlet check valve prevents cross contamination by blocking inhalation through the indicator. A disposable breath inlet tube makes sterilization unnecessary between uses from patient to patient. According to one aspect of the invention, the indicator may be adapted for anesthesiology use, the hot junction then being located in an elbow connecting the gas supply tube and the disposable treachea tube.

Abstract: The present invention is directed to a circuit for generating a voltage for compensating the output of a thermocouple. The circuit provides a compensating voltage to enable the thermocouple to be operated with its reference junction at ambient temperature. The compensation voltage varies linearly with changes in the ambient temperature and passes through zero volts at 0-20 C. The compensation voltage is generated by combining a temperature variable voltage developed across one or more semiconductor junctions with a constant voltage of opposite polarity.

Abstract: A hand-held digital readout thermometer measures temperatures over the range -50.degree. C. to +1100.degree. C. with a maximum error less than 3.degree. C. in that range. The thermometer includes a thermocouple, a temperature stable and temperature independent power supply, a temperature stable differential first amplifier, a second amplifier that compensates for the nonlinear response of thermocouple voltage to temperature, and an analog/digital converter controlling a digital display indicating temperature according to a preselected scale. A particular feature of the invention is a latching comparator capable of activating a low battery indicator when the supply voltage drops below a preselected value.

Abstract: An electronic measuring device utilizes multiple different transducers for supplying signals exhibiting predetermined and typically nonlinear relationships to the multiple input variables sensed by the transducers. The measuring device includes a microcomputer containing stored linearizing information therein relating to the predetermined nonlinear relationship of the signals supplied by the transducers and the variables sensed by the transducers. The microcomputer linearizes each of the signals supplied by the transducers and thereby obtains highly accurate signals indicative of the variables sensed. Depending upon the ultimate determination to be obtained by the device, the linearized signals representative of the input variables may be employed in a polynomial equation calculation conducted by the computer to obtain the output determination.

Abstract: A kiln temperature controller is provided comprising a circuit for providing a first signal representative of a selectable kiln temperature and a temperature detection circuit for providing a second signal representative of the detected kiln temperature. The temperature detection circuit comprises first and second thermocouples disposed in the kiln and in the temperature controller, respectively. The first and second thermocouples are coupled in series and in opposite polarity. A solid state temperature sensing circuit is provided in the kiln temperature controller, the temperature sensing circuit being coupled in series with the first and second thermocouples and providing an output signal having a polarity opposite that of the second thermocouple to nullify ambient temperature variations of the kiln temperature controller.

Abstract: This disclosure is concerned with a novel digital multi-point recorder that is microprocessor-controlled and enables impact printing from in back of the recorder paper to provide a front visible flat print-out of pages of on-line running summary data suited for operator viewing in industrial and similar locations, and providing a record for direct use in reports and logs.