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For accurate measurements, the chosen mounting method needs to provide a bond line free of visible voids. Thin bonds maximize respone. Continuous thin bonds are achieved by any of the following methods.
The ease of installation of the Micro-Foil® sensors makes their applications almost unlimited.
The thin and flexible sensors can be attached to flat or curved surfaces and may be permanently bonded in place with conventional adhesives or epoxies.
A convenient method for continued re-use at numerous locations is their installation using double adhesive-backed mylar tape. Upon installation, simply connect the leads to a millivoltmeter or similar readout device and a direct measurement of the surface heating or cooling rate in Btu–ft–-2-h–1 or equivalent units is provided.
For a single use temporary installation, Micro-Foil® heat flow sensors may be ordered with optional pressure sensitive adhesive (PSI) on the mounting surface. The adhesive layer is protected with a release sheet which is removed for use.
There are other cases where heat flow data is required over a long or extended period. The best method of insuring stable installation for the entire period is to provide a permanent installation. Each user may have his own preference as to an adhesive for mounting the sensor. A few recommendations which have been found satisfactory for past applications are as follows: for attachment to very smooth surfaces much as metallic, plastic or glass surfaces, cements such as Eastman No. 910 have been very satisfactory. For roughened surfaces such as walls, liquid epoxy, or a fast setting RTV are useable to temperatures as high as 250°F. This type of epoxy also has the advantage of curing at room temperature. For the few instances where a high temperature epoxy is desired, Emerson-Cuming No. 104 is useable to in excess of 450°F. However, the use of this adhesive requires an elevated temperature cure such as in an oven or use of radiant heat lamps.
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