Induction pen with Guerra Verbatim Corporation, a hand touch membrane surface, the other hand induction pen (fingers touch induction pen electrode), and use the tip to touch the surface to be measured, to see if the light or hear the sound, can be judged as the membrane surface, the pen is also based on the principle of film conductive design;

Two, the instrument detection method.

1 you can use professional film detector, convenient, accurate, plastic surface in contact with glass, will not scratch the glass, its biggest advantage is also able to detect what is film face seal in the glass coating film surface conditions;

2 can also be made of the membrane surface, can be converted into small multimeter measuring membrane surface. The coating layer is a metal material, can be used to measure resistance identification of membrane surface, which is convenient to use, it is not easy to scratch the glass;

Three, empirical observation method.

1 experienced employees, touch the surface of the glass by hand, smooth surface for the glass surface, non smooth membrane surface, but on the quality of coated glass, membrane surface and the glass surface is very smooth, very difficult to judge accurately. This method is simple, but has slightly carelessly will hurt the film surface;

2 use lights or lighter flame, against the glass side to see, if there are two light, light red side membrane surface, no changes in the light of the glass surface;

3 see shadow pencil judgment, will cut lead pencil, pen contact inclination of measured surfaces (45 ° - 60 ° advisable) volume, if you can see shadows from surface two is not the membrane surface, the other side is the glass surface (this method is especially suitable for heat reflecting coated glass).

4 for coated glass manufacturers cutting, strict requirements for such a film, according to the Department of glass cutting back signs of judgment, the rough edge of one side of the membrane surface, edge smooth side to the glass surface.

Four, with the discriminant glass surface method.

Ultraviolet tin apparatus, but also can measure the membrane surface, is not a tin surface is a surface. In addition to pay attention to heat reflection glass film is not conductive, method one or two is not applicable.