Electronic balance meter

• US 4,511,791 A
• Filed: 04/25/1983
• Issued: 04/16/1985
• Est. Priority Date: 04/25/1983
• Status: Expired due to Fees

• Current Assignee: Owens- Corning Fiberglas Technology Incorporated (Owens Corning)
• Original Assignee: Owens-Corning Fiberglas Corporation
• Inventors: Kreikebaum, Gerhard, Desai, Avinash J.
• Primary Examiner(s): Paschall, M. H.
• Application Number:
  US06/488,489
• Time in Patent Office: 722 Days
• Field of Search: 219/494, 219/490, 219/497, 219/483, 219/485, 219/486, 219/501, 219/497, 219/508-510, 219/201, 364/577, 364/482, 364/483, 65/1, 65/12, 65/162, 65/164
• US Class Current: 219/497
• CPC Class Codes: C03B 37/07 Controlling or regulating C03B37/0253 takes precedence ; controlling or regulating in general G05
• CPC Class Codes: G05D 23/2401 using a heating element as a sensing element

Abstract

The bushing temperature measurement device is a microprocessor based sensor which determines the temperature across a multi-segment electrical resistance heated glass fiber producing bushing. The temperature change is determined by calculating the change in resistance of each segment of the bushing by sensing the voltage drop across that segment and dividing by the current flowing in that segment. All measurements of voltage and current are taken simultaneously and averaged over several cycles. The microprocessor, through appropriate output circuitry, alerts other process controls to eliminate any change in temperature.

Claims

1. An apparatus for measuring the temperature is segments of an electrical resistance heated glass fiber producing bushing and for displaying the change in temperature of each segment of the bushing comprising:

(a) a glass fiber producing bushing, compartmentalized into individual segments, electrically heated by passing an electrical current through the bushing;

(b) means to supply an electrical current to flow in the bushing;

(c) means for determining the electrical current flowing in a glass fiber producing bushing;

(d) means for simultaneously determining a voltage drop across each segment of the glass fiber producing bushing;

(e) means to calculate a resistance and a temperature from the resistance for each segment of the glass fiber producing bushing;

(f) means for storing the temperature of each segment of the glass fiber producing bushing;

(g) means for determining a change in temperature by use of the stored temperature for each segment of the glass fiber producing bushing;

(h) means for indicating that the change in temperature of any of the segments of the glass fiber producing bushing is outside a predetermined range; and

(i) means to display the change in temperature of each segment of the glass fiber producing bushing.

2. An apparatus for measuring the temperature in segments of an electrical resistance heated glass fiber producing bushing comprising:

(a) a glass fiber producing bushing, compartmentalized into individual segments, electrically heated by passing an electrical current through the bushing;

(b) a means to produce a signal proportional to an electric current flowing in the glass fiber producing bushing;

(c) a means to simultaneously sense a voltage drop across each segment of a multiple segment glass fiber producing bushing;

(d) a means to simultaneously read the signal from (a) and the voltages from (b) above, to digitize the signal and the voltages and to determine by means of a microprocessor the change in temperature of each segment of the glass fiber producing bushing;

(e) means to determine if the change in temperature of each segment of the glass fiber producing bushing is within a predetermined range;

(f) means to communicate the change in temperature to external devices including a computer; and

(g) means to indicate that the temperature change is outside a predetermined range.

3. An apparatus for measuring the temperature in segments of a glass fiber producing bushing comprising:

(a) a glass fiber producing bushing, compartmentalized into individual segments, electrically heated by passing an electrical current through the bushing;

(b) a means for sensing an electrical current flow in the primary winding of a glass fiber producing bushing power transformer;

(c) a means to connect the current sensed in the primary winding of a glass fiber producing bushing power transformer to a voltage proportional to the current sensed;

(d) a means for simultaneously sensing a voltage dropped across each segment of a glass fiber producing bushing;

(e) a means for simultaneously reading and digitizing the voltage signals of (c) and (d) above;

(f) microprocessor means for calculating a change in temperature of each segment of the glass fiber producing bushing on the basis of the formula;

##EQU7## wherein;

Δ

T_i =change in temperature of segment i from a set point temperature;

α

=resistivity change per degree Fahrenheit for the metal used in the bushing;

E_i =voltage drop across segment i at time of measurement;

Em=voltage drop across primary circuit at time of measurement;

E_i¹ =voltage drop across segment i at time of calibration of set point temperature;

Em¹ =voltage drop across primary circuit at time of calibration at set point temperature;

(g) means for producing an output signal proportional to the value of Δ

T_i ; and

(h) means for indicating if the output signal Δ

T_i is outside a predetermined range of values.

4. An apparatus for measuring the temperature across the face of an electrical resistance heated glass fiber producing bushing comprising;

(a) a glass fiber producing bushing, compartmentalized into individual segments, electrically heated by passing an electrical current through the bushing;

(b) means for simultaneously measuring the voltage drop across each segment of the bushing;

(c) means for measuring a current flowing in the bushing;

(d) means for calculating a resistance for each segment of the bushing from the current and voltage drop measured;

(e) means for calculating a temperature from the resistance calculated for each segment of the bushing; and

(f) means to store the value of the temperature calculated.

5. A method for measuring the temperature in an electrical resistance heated glass fiber producing bushing comprising the steps of:

(a) compartmentalizing a glass fiber producing bushing into undeveloped segments;

(b) flowing an electric current through the bushing to electrically resistance heat the bushing;

(c) determining the current flowing in the bushing;

(d) simultaneously sensing a voltage drop across each segment of the bushing;

(e) deriving a resistance of each segment of the bushing by dividing the current flow in the bushing into the voltage drop across each segment of the bushing;

(f) converting the resistance of each segment of the bushing into a temperature for each segment;

(g) storing the temperature for each segment of the bushing;

(h) repeating steps (c) through (f) above to determine a new temperature for each segment of the bushing;

(i) determining the difference between the stored temperature and the new temperature for each segment of the bushing; and

(j) indicating when the difference in temperature is outside a predetermined range.

6. A method for measuring the temperature in segments of electrical resistance heated glass fiber producing bushing and for displaying the change in temperature of each segment of the bushing comprising the steps of;

(a) compartmentalizing a glass fiber producing bushing into individual segments;

(b) flowing an electric current into a primary winding of a step down power transformer;

(c) connecting a secondary winding of the power transformer to the bushing such that the flow of current heats the bushing by electrical resistance means;

(d) sensing the electrical current flowing in the primary winding of the power transformer;

(e) converting the current sensed into a voltage signal (E_m) proportioned to the current flowing in the primary winding of the power transformer;

(f) simultaneously sensing a voltage (E_i) across each segment (i) of the bushing;

(g) storing the voltage signal (E_m) and simultaneously storing each voltage signal (E_i);

(h) sensing a new electrical current flowing in the primary winding of the power transformer;

(i) converting the new current sensed into a new voltage signal (Em¹) proportioned to the current flowing in the primary winding of the power transformer;

(j) simultaneously sensing a new voltage (E_i¹) across each segment (i) of the bushing;

(k) generating a scaling signal (α

);

(l) calculating with a microprocessor a change in temperature (Δ

T_i) based on the equation;

##EQU8## (m) displaying the value Δ

T_i to a display device; and

(n) activating an alarm if the value of Δ

T_i is outside a predetermined range.