Defence Standard 00-23 Issue 4 - Sandtec AS

Annex ADetermination of Infra Red ReflectanceDEF STAN 00-23 Issue 4A.1 Test Sample PanelThe test panel shall be prepared and painted in accordance with the relevant material standard withparticular reference to the specified full paint scheme and dry film thickness. In the absence of a specificmaterial standard, the test panel shall be prepared and painted in accordance with the paint manufacturersinstructions and the agreement of the responsible Technical Authority named in the contract or order.A.2 ApparatusA.2.1 A recording spectrophotometer fitted with an integrating sphere. Illumination of the sample shall beat an angle not exceeding 10° from the normal. Measurements shall be made with the specular componentof reflection, included in the 8°/t geometry. The instrument shall meet the following requirements:Measuring rangeWavelength accuracy400 nm to 1200 nm± 5 nmMeasuring accuracy ± 2%A.2.2 The 100% baseline shall be calibrated using a reflectance standard that is traceable to a NationalStandard. Between the wavelengths 400 nm to 1200 nm the standard shall have an absolute reflectance atleast 98%. Reflectance grade PTFE, such as Spectralon, has been found to be suitable.A.3 ProcedureUsing the spectrophotometer in accordance with the manufacturer’s instructions, obtain the reflectance ofthe painted panel surface at 10 nm intervals over the range specified in Table 1.3