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US 2015/0085897 A1Published application
Infrared sensor
AssigneeRosemount Inc.
InventorJason Harold Rud
Life of this patent
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Abstract
An infrared sensor includes a thermopile connected in series with an ambient temperature compensation resistance temperature detector (RTD) and four electrical leads. The thermopile produces a voltage as a function of temperature of a point of interest, while the RTD varies in resistance as a function of ambient temperature. Two of the leads deliver current to energize the RTD. The other two leads are used for sensing voltages produced by the thermopile and the RTD.
Claims20
An infrared sensor comprising:
- a thermopile for producing a voltage as a function of temperature of a point of interest;
- a resistance temperature detector (RTD) that varies in resistance as a function of ambient temperature, the RTD connected in a series circuit with the thermopile;
- first and second leads connected to the RTD;
- a third lead connected to the RTD and the thermopile;
- and
- a fourth lead connected to the thermopile.
3 more elements
An infrared sensor comprising:
- a resistance temperature detector (RTD) having a first RTD terminal and a second RTD terminal;
- a thermopile having a first thermopile terminal and a second thermopile terminal, the first thermopile terminal connected to the second RTD terminal;
- a first excitation current lead connected to the first RTD terminal;
- a second excitation current lead connected to the second RTD terminal;
- a first voltage sensing lead connected to the first RTD terminal;
- a second voltage sensing lead connected to the second thermopile terminal;
- and
- measurement circuitry for providing a temperature measurement value based upon a first voltage between the first and second voltage sensing leads when no excitation current flows through the first and second excitation current leads, and a second voltage between the first voltage sensing lead and either the second voltage sensing lead or the second excitation current lead when excitation current flows through the first and second excitation current leads.
5 more elements
Dependencies are inferred from the claim text.