Multi-layered thin film heat transfer gauge

Claim 1

A multi-layered heat transfer gauge, comprising a heat resistive thin film having a heat conductivity κ and a thickness L between upper and lower opposite surfaces; a first metallic thin film having a resistance r 1 and a temperature coefficient of resistance a 1 bonded to the upper surface of said heat resistive thin film and a second metallic thin film having a resistance r 2 and a temperature coefficient of resistance a 2 bonded to the lower surface of said heat resistive thin film; and measuring means for measuring the temperature gradient across said heat resistive thin film, said measuring means including a first resistor R 1 connected in series with said first metallic thin film to form a first series circuit; a second resistor R 2 connected in series with said second metallic thin film to form a second series circuit; and third and fourth resistor R S and r s respectively connected in series to form a third series circuit, said first, second and third series circuits being connected in parallel, a voltage V being connected across the parallel connection of said first, second and third series circuits, a voltage e 1 being generated at the connection of said first resistor and said first metallic thin film, a voltage e 2 being generated at the connection of said second resistor and said second metallic thin film and a voltage e 0 being generated at the connection of said third and fourth resistors, whereby the heat flux qw entering said heat resistive thin film is given by the equation: qw=γ(ε.sub.12 +δ·ε.sub.20), where ε 12 =(e 1 -e 2 )V ε 20 =(e 2 -e 0 )/V δ=(a 2 -a 1 )/a 2 ; and γ=(κ/L)·(1/a 1 )·(m+1) 2 /m, where m=R s /r s .