RayTek MI Miniature Infrared Sensor - Manual (Page 20)

Basics
12 MI
4.2 Emissivity of Target Object
To determine the emissivity of the target object refer to section 12.1
Determination of Emissivity on page 81. If emissivity is low,
measured results could be falsified by interfering infrared radiation
from background objects (such as heating systems, flames, fireclay
bricks, etc. close beside or behind the target object). This type of
problem can occur when measuring reflective surfaces and very thin
materials such as plastic films and glass.
This measurement error can be reduced to a minimum if particular
care is taken during installation, and the sensing head is shielded
from these reflecting radiation sources.
4.3 Ambient Temperature
The sensing head was developed for the following ambient
temperature ranges:
• MIH: 0 to 180°C (32 to 356°F)
• MIC: 0 to 125°C (32 to 257°F)
• MID: 0 to 85°C (32 to 185°F)
The MID can operate in ambient temperatures up to 200°C (392°F)
with the air‐cooling accessory.
4.4 Atmospheric Quality
If the lens gets dirty, infrared energy will be blocked and the
instrument will not measure accurately. It is good practice to always
keep the lens clean. The Air Purge Jacket helps keep contaminants
from building up on the lens. If you use air purging, make sure a
filtered air supply with clean dry air at the correct air pressure is
installed before proceeding with the sensor installation.