Thermal conductivity vacuum gauge assembly
The present disclosure relates to a thermal conductivity vacuum gauge assembly. The assembly comprises a body defining an internal chamber for receiving working gas and a heater element disposed within the chamber. The body is defined by a wall having an outer facing wall surface and an opposing inner facing wall surface. A thermal compensation element and a thermal equalisation element are in thermal communication with the body. The body is made of a material with a first thermal conductivity, and the thermal equalisation element is made of a material with a second thermal conductivity that is higher than the first thermal conductivity. The present disclosure also relates to a thermal conductivity vacuum gauge including the assembly.
1 . A thermal conductivity vacuum gauge assembly comprising:
a body defining an internal chamber for receiving working gas, wherein the body is defined by a wall having an outer facing wall surface and an opposing inner facing wall surface;
a heater element disposed within the chamber;
a thermal compensation element in thermal communication with the body; and
a thermal equalisation element in thermal communication with the body;
wherein the body is made of a material with a first thermal conductivity, and the thermal equalisation element is made of a material with a second thermal conductivity that is higher than the first thermal conductivity.
2 . The assembly of claim 1 , wherein the thermal equalisation element at least partially surrounds the internal chamber and is in thermal contact with the body.
3 . The assembly of claim 2 , wherein the thermal equalisation element at least partially surrounds the outer facing wall surface.
4 . The assembly of claim 3 , wherein the thermal equalisation element forms an outer sleeve around the body.
5 . The assembly of claim 3 , wherein the thermal equalisation element comprises at least one strip extending along the body.
6 . The assembly of claim 1 , wherein the second thermal conductivity is at least 10 times greater than the first thermal conductivity.
7 . The assembly of claim 1 , wherein the body is made of stainless steel and the thermal equalisation element is made of aluminium.
8 . The assembly of claim 1 , wherein the thermal compensation element is located within a cavity defined in the wall.
9 . The assembly of claim 1 , further comprising an electrical connection member mounted to the thermal compensation element, wherein at least some of a first portion of the electrical connection member is surrounded by the thermal equalisation element and a second portion of the electrical connection member protrudes out from the body.
10 . The assembly of claim 1 , wherein:
the body extends along a longitudinal axis between a base and a top and has a sidewall extending between the base and the top; and
the thermal equalisation element at least partially surrounds the sidewall and extends axially along the longitudinal axis.
11 . The assembly of claim 10 , wherein the body includes a radially extending shoulder that abuts the thermal equalisation element.
12 . The assembly of claim 10 , wherein the base defines an inlet passage in fluid communication with the chamber, and includes a radially extending flange with a recess therein for receiving a seal.
13 . The assembly of claim 1 , wherein the heater element is a filament for heating by an electrical power source.