Temprange; Emissivity - Fluke VT08-II User Manual

VT06/VT08/VT08-II
Users Manual

TempRange

When measuring temperature, you need to use the appropriate temperature range, which
depends on the target temperature. The Meter has these temperature ranges:
-20 °C to 150 °C (-4 °F to 302 °F)

100 °C to 400 °C (212 °F to 752 °F)

The Meter can automatically use the appropriate range based on the target temperature if you
set the TempRange to Auto in the Main Menu.

Emissivity

All objects radiate infrared energy. The actual surface temperature and emissivity of the target
affect the quantity of energy radiated. The Meter senses the infrared energy from the surface
of the target and uses the data to calculate an estimated temperature value. Many common
materials such as wood, water, skin, cloth, and painted surfaces, including metal, radiate
energy well and have a high emissivity factor of ≥90 % (or 0.90). The Meter measures
temperatures accurately on targets with a high emissivity.
Shiny surfaces or unpainted metals do not radiate energy well and have a low emissivity factor
of <0.60. For the Meter to calculate a more accurate estimate of the actual temperature of
targets with a low emissivity, adjust the emissivity setting.
To prevent personal injury, see emissivity information for actual temperatures.
Reflective objects result in lower than actual temperature measurements. These
objects pose a burn hazard.
Set emissivity as a direct value or from a list of emissivity values for some common materials.
Surfaces with an emissivity of <0.60 make it difficult to determine reliable and
consistent actual temperatures. The lower the emissivity, the greater the potential of
error when the Meter calculates the temperature measurement because more of the
energy reaching the camera is specified as background temperature. This is also true
when adjustments to the emissivity and reflected background adjustments are
performed properly.
To adjust emissivity:
1. In the Emissivity submenu, push W or X to select which emissivity to use, or select
SelfDefine.
2. If you select SelfDefine, push
O
3. Push again to save.
P
4. Push to return to the previous menu.
12
W Warning
Note
O
and W or X to manually set the emissivity.