US 11,841,282 B2
Strain gauge insulated against moisture penetration and method of manufacturing same
XiangQun Zhu, Changzhou (CN); Zhiguo Shi, Changzhou (CN); Lei Xu, Changzhou (CN); and Jean-Christophe Emery, Changzhou (CN)
Assigned to Mettler-Toledo (Changzhou) Precision Instrument Co. Ltd., Changzhou (CN); Mettler-Toledo (Changzhou) Measurement Technology Co. Ltd., Changzhou (CN); Mettler-Toledo International Trading (Shanghai) Co. Ltd., Shanghai (CN); and Mettler-Toledo GmbH, Greifensee (CH)
Appl. No. 17/269,910
Filed by Mettler-Toledo (Changzhou) Precision Instrument Co. Ltd., Changzhou (CN); Mettler-Toledo (Changzhou) Measurement Technology Co. Ltd., Changzhou (CN); Mettler-Toledo International Trading (Shanghai) Co. Ltd., Shanghai (CN); and Mettler-Toledo GmbH, Greifensee (CH)
PCT Filed Aug. 30, 2019, PCT No. PCT/EP2019/073246
§ 371(c)(1), (2) Date Feb. 19, 2021,
PCT Pub. No. WO2020/043892, PCT Pub. Date Mar. 5, 2020.
Claims priority of application No. 18191935 (EP), filed on Aug. 31, 2018.
Prior Publication US 2021/0262873 A1, Aug. 26, 2021
Int. Cl. G01L 1/00 (2006.01); G01L 1/22 (2006.01); G01L 1/26 (2006.01)
CPC G01L 1/2287 (2013.01) [G01L 1/2243 (2013.01); G01L 1/26 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A strain gauge insulated against moisture penetration, the strain gauge comprising:
a base layer of a polymer substrate foil material;
a resistor track layer on a metallic resistive foil material, the resistor track being in the shape of a meandering structure and having electrode pads for contacting the resistor track, the resistor track layer being laminated together with the base layer; and
a strain gauge produced by means of a chemical etching method on the laminated base and resistor track layers;
wherein at least one of the following obtains:
a moisture barrier coating is formed, by means of a deposition process, on all sides of the base layer so that the moisture barrier coating encapsulates the base layer; or
the strain gauge further comprises a cover layer of a polymer film foil material and with a moisture barrier coating formed, by means of a deposition process, on at least one side of the cover layer, providing a coated cover layer that is overlaid on the surface of the resistor track layer to cover at least part of the strain gauge.