Dry Film Thickness Gauge Test Anticorrosive Coating Thickness

Architectural buildings and urban public facilities such as guardrails all use steel structures as part of the building. It can be said that the steel structure is widely used in production and construction. In order to better and faster accept the project, the country has made relevant thickness regulations for steel structure fireproof coating products. "Code for Acceptance of Construction Quality of Steel Structure Engineering" GB50205-2001 Section 14 wrote: "Steel Structure Coating Engineering" Section 14.2.2 Main Control Items: "Paint, coating passes, coating thickness should all meet design requirements. The allowable deviation of the dry paint film thickness for each pass is -5μm. When there is no requirement for the coating thickness, the total dry paint film thickness: 150μm for outdoor and 125μm for indoor. The allowable error range is -25μm.

1. Fireproof coatings for steel structures can be divided into:

Indoor steel structure fire retardant coating, that is, the steel structure surface used for indoor or concealed works of buildings

Outdoor steel structure fire retardant coating is used on the steel structure surface of outdoor or open-air works of buildings.

Fire-retardant coatings usually need to be controlled within the specified thickness range in order to give full play to its fire resistance. If the paint is applied too much, it is easy to cause peeling. If the paint is insufficient, the fire resistance will be greatly reduced. In order to check whether the paint thickness is within the qualified range, it is usually necessary to use a professional dry film thickness gauge. We can use a dry film thickness gauge to measure five points on the object surface and take the average value.

2. Steel structure fireproof coating thickness testing -dry film thickness gauge

Dry film thickness gauges usually use magnetic induction thickness measurement or eddy current thickness measurement principles. The materials tested by the dry film thickness gauges of the two principles are different.

• Magnetic induction dry film thickness gauge is suitable for measuring non-ferromagnetic coatings (varnish, paint, enamel, chromium, galvanized) on ferromagnetic metals (such as steel and iron).

• The eddy current dry film thickness gauge is suitable for measuring the non-conductive coating (paint, anodized layer or ceramic) on the non-ferromagnetic metal substrate (aluminum, copper, die-cast zinc, brass).  

To measure the fireproof coating thickness on steel structure, magnetic induction dry film thickness gauge is needed. Linshang LS221 is a corrosion thickness gauge that uses both magnetic induction and eddy current principles. LS221 dry film thickness gauge is widely used in metal processing industry, coating industry, shipbuilding industry, aerospace industry and other fields. The instrument adopts advanced digital probe technology, which can keep the zero position stable and not drift for a long time, without frequent zero adjustment.

If you need to know more about the thickness measurement of steel structure coating, please call us at sales21@linshangtech.com.