Window Film Transmission Meter Selection and FAQ

The two bands of 940nm and 1400nm are relatively representative bands. Most of the absorption films (heat-absorbing films) have better infrared blocking effect at 940nm, while the magnetron sputtering reflection film has better blocking effect at 1400nm such as metal film and ceramic nano film. Please choose the right instrument for your own film category.

The metal film is produced by a magnetron sputtering process. A large amount of metal elements are added and the has a good reflection ability to the infrared film. It is insulated by the principle of reflecting infrared rays.

The absorption film is added with an infrared absorber during production and the infrared is absorbed by the film. It is insulated by the absorption principle and secondary heat radiation will be generated after the heat absorption is saturated.

Each film tested by both 940nm and 1400nm instruments will have infrared blocking rate data. Due to different production processes, the thermal insulation data of some films at 940nm will be larger than the thermal insulation data of 1400nm. Some films will have larger thermal insulation data at 1400nm.

E.g: Vickers V70 has an official infrared rejection rate of 98%. The measurement data tested by 1400nm instrument is about 98%, while the measurement data tested by 940nm instrument is only about 88%.

The 3M Jingrui 70 has an official infrared rejection rate of 98%. The measurement data tested by 940nm instrument is about 99%, while the measurement data tested by 1400nm instrument is only about 87%.

There are too many types of films and the data differences between 940nm and 1400nm are also very different. Some films may not differ much and some films differ by 30-40%, so we can't tell you the exact value.

It's all about the cost of raw materials. The cost of a 1400nm light source and receiver is much higher.

Our instrument measures the infrared rejection rate. The higher the infrared rejection rate, the higher the thermal insulation rate. Because visible light also has a small amount of heat, in the strict sense, the heat insulation rate needs to integrate visible light, infrared and ultraviolet heat insulation data. Ultraviolet heat is very small and visible light is beneficial. Therefore, infrared is the main source of heat, so the infrared rejection rate is basically equivalent to the thermal insulation rate.

The LS300 measures the real-time temperature (degrees Celsius) and the temperature difference. The price is $135. The LS301 has a function to measure the infrared rejection rate of 940nm than the LS300. At the same time, the LS301 also measures the real-time temperature value. The price is $150.

The two demo kits differ only in the wattage of the infrared light. The SK1150 lamp is 150W and the SK1250 lamp is 250W. The operation of the two kits is the same. Generally speaking, 150W is enough, but the 250W lamp shows a much larger light intensity value during the demonstration. After the material is put in, the difference in light intensity value is larger.

The parameters of the new and old models are basically the same, both of which can measure three parameters of heat insulation, UV rejection and light transmission.

The old model can only be used when plugged in. It is a digital tube display. The new model is an LCD display. It uses 4 AA batteries and has a USB interface on the instrument. It can be directly powered by a power bank or 5V charging head.

The light source of the old LS101 is a point light source, which is only suitable for films and thin glass; the new LS101 uses a parallel light path design and thick glass can also be tested.