Method for in-situ restoration of platinum resistance thermometer calibration

Patent · Tue Jan 03 00:00:00 EST 1989

OSTI ID:6468478

Carroll, R M

A method is described for the in situ restoration of a platinum resistance thermometer, which has become decalibrated due to oxide surface film formation and/or strain-related damage, to a stress-free calibration condition wherein the thermometer includes a platinum resistor sensing element whose resistance varies with the temperature of the element in accordance with a known relationship. The method consists of: passing a controlled dc current through the platinum resistor sensing element, the current having a magnitude sufficient to raise the temperature of the element to its oxide decomposition and annealing temperature. The current is maintained for a heating period sufficient to restore the element to an oxide free surface and stress-free calibration condition.

• Assignee: Dept. of Energy, Washington, DC
• Patent Number(s): US 4795884
• OSTI ID: 6468478
• Resource Relation: Patent File Date: Filed date 23 Oct 1987
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
THERMOMETERS
DESCALING
ANNEALING
CALIBRATION
CORROSION
DAMAGE
DECOMPOSITION
DEPOSITS
DIRECT CURRENT
OXIDATION
OXIDES
PLATINUM
RESISTORS
TEMPERATURE EFFECTS
TEMPERATURE MEASUREMENT
THERMAL CONDUCTIVITY
CHALCOGENIDES
CHEMICAL REACTIONS
CURRENTS
ELECTRIC CURRENTS
ELECTRICAL EQUIPMENT
ELEMENTS
EQUIPMENT
HEAT TREATMENTS
MEASURING INSTRUMENTS
METALS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLATINUM METALS
SURFACE FINISHING
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
440400* - Well Logging Instrumentation