B) Distance-To-Spot Ratio (D:s) - BASETech IRT-350 Bedienungsanleitung

• Emissivity is a value that quantifies a material's ability to emit energy via radiation. The higher
this value, the higher the material's ability to radiate energy. Many organic materials and
surfaces have an emissivity of approx. 0.95. Metallic or reflective materials have a lower
emissivity and therefore give less reliable readings. It is therefore recommended to apply a
layer of matt black paint or matt tape to metallic or reflective surfaces.

b) Distance-to-spot ratio (D:S)

• In order to achieve reliable readings, the entire measuring object must be larger than the
thermometer's measuring surface (IR measuring spot). The calculated temperature is the
average temperature of the measured surface.
• The smaller the measuring object is, the lesser the distance between the thermometer and
the measuring object should be.
• For exact readings, the measuring object should be at least twice as large as the IR measuring
spot.
• The ratio distance to IR measuring spot size is 10:1. At a distance of 10 cm from the measuring
object, the IR measuring spot has a size of 1 cm.
• Review the following diagram for the exact size of the IR measuring spot:
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