Wireless data gathering system for molten metal processing

• US 5,319,576 A
• Filed: 08/05/1987
• Issued: 06/07/1994
• Est. Priority Date: 08/05/1987
• Status: Expired due to Term

• Current Assignee: L&N Metallurgical Products Co. (Heraeus Holding GMBH)
• Original Assignee: General Signal Corporation (SPX Corporation)
• Inventors: Iannadrea, Gerald
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): Zawelli, Michael
• Application Number:
  US07/082,020
• Time in Patent Office: 2,498 Days
• Field of Search: 364/496, 364/497, 364/557, 340/825.07, 340/870.13, 340/870.17, 374/140
• US Class Current: 702/130
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 15/007 Testing
• CPC Class Codes: G08C 17/02 using a radio link

Abstract

A system for obtaining real time measurements of at least one variable, such as temperature, of a molten metal bath where the variable is measured by immersion of an expendable primary element. The system includes a data transmitting assembly which receives the output of the primary element and when that output is within a predetermined range, indicating a valid reading, transmits a digital radio signal indicative of the magnitude of the variable. A data receiving assembly operates to receive the transmitted radio signal and a display device responsive to the output of the receiving device displays the magnitude of the variable.

Claims

1. A system for obtaining real time measurements of a variable of a molten metal bath where the magnitude of the variable is measured by the immersion into the molten metal of a primary element for detecting said variable, and said primary element is an expendable device which plugs into the end of a lance for immersion into the molten metal and unplugs from the lance after the measurement is made and the lance is withdrawn from the molten metal, comprising

a data transmitting assembly connected to receive the output of said primary element and operable to convert that output to a digital form and to transmit a radio signal indicative of the magnitude of said digital form only when the magnitude of said variable is within a predetermined range, which indicates that the primary element is plugged into said lance and that it is providing a valid reading;

a data receiving assembly operable to receive said transmitted radio signal; and

a display device responsive to the output of said data receiving assembly to display the magnitude of said variable.

2. A system as set forth in claim 1 in which there are a plurality of primary elements to measure a corresponding number of variables of the molten metal bath and

said data transmitting assembly includes a multiplexer for scanning a plurality of said primary elements;

and

said receiving assembly includes a separate digital-to-analog converter for converting signals relating to each of said primary elements.

3. A system for obtaining real time measurements of a variable in molten metal processing, comprising;

a sensor operable to detect the magnitude of said variable;

a data transmitting assembly having

an analog to digital converter connected to the output of said sensor for converting the detected values of the associated variable to a digital form at the output of the converter,

a microprocessor connected to receive said digital form of said detected values and operable to output said values only if said values are within a range of values which would indicate that valid measurements were being made by said sensor, said microprocessor also being operable to time the operation of said transmitting assembly,

a frequency modulated very high frequency radio transmitter, and

a modulator responsive to the output of said microprocessor and operable to modulate the frequency of said transmitter in accordance with said output from said microprocessor;

a data receiving assembly having

a frequency modulated very high frequency radio receiver responsive to signals from said transmitter,

a demodulator operable to demodulate the received signal,

a microprocessor responsive to the demodulated signal and operable to process said signal, and

a digital-to-analog converter operable to convert the digital signal output of the microprocessor to an analog signal; and

a display connected to the output of said digital-to-analog converter for exhibiting the magnitude of said variable.

4. A system for obtaining real time measurements of a plurality of variables in molten metal processing, comprising;

a plurality of sensors operable to detect the magnitude of those of said variables measuring said molten metal conditions;

said sensors including a thermocouple having hot and cold junctions for measuring the temperature of said molten metal;

a supplementary thermocouple sensor positioned to measure the ambient temperature in the region of the cold junction of said measuring thermocouple;

a sensor for detecting the potential at a ground terminal;

a data transmitting assembly having

a multiplexer for scanning said sensors,

an analog to digital converter connected to the output of said multiplexer for converting the outputs of the associated sensors to a digital form at the output of the converter,

a microprocessor connected to receive said digital form of said sensor outputs and operable to output said digital form only if the values of said outputs are within a range of values which would indicate that valid measurements were being made, said microprocessor also being operable to time the operation of said transmitting assembly and to make calculation of the temperature of the molten metal taking into account the cold junction temperature and the ground potential,

a frequency modulated very high frequency radio transmitter, and

a modulator responsive to the output of said microprocessor and operable to modulate the frequency of said transmitter in accordance with said output from said microprocessor;

a data receiving assembly having

a frequency modulated very high frequency radio receiver responsive to signals from said transmitter,

a demodulator operable to demodulate the received signal,

a microprocessor responsive to the demodulated signal and operable to process said signal, and

a digital-to-analog converter operable to convert the digital signal output of the microprocessor to an analog signal; and

a display connected to the output of said digital-to-analog converter for exhibiting the magnitudes of said variables.