Siemens 7MC3040-..., Operating Manual, Page: 25 / 116

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Operating manual PA
17
A pyrometer measures temperature by detecting the radiant energy emit-
ted from an object’s surface in the form of electromagnetic waves. The
temperature reading not only depends on the intensity of the object’s
thermal radiation (how hot the object is), but als
o on the material’s par-
ticular surface characteristics and thus its specific ability to emit thermal
energy. This is called emissivity. To obtain an accurate temperature
reading, it is imperative that the pyrometer be adjusted for this emissivity
prior to measurement.
Set the emissivity correction at configuration layer
C001 .
See the
Emissivity Coefficient Table in Chapter 12 to select the proper emissivity
factor for your application. We recommend that you first perform a com-
parison temperature measurement with another device to determine the
correct emissivity factor for the task.

NOTE !
During normal operating mode, emissivity can be set at the py-
rometer using the
▲▼
buttons. When simultaneously pressing
the MODE key, the display shows the current measuring tempera-
ture while the emissivity coefficient continues to be adjusted in the
background. This is an easy way to determine the emissivity when
the object temperature is known. The modified values are directly
adopted.
CAUTION!
Once you have configured the emissivity parameter, the py-
rometer will maintain this specific setting. The pyrometer will
always operate with this value unless you change the setting.
6.8 Output current range
For the pyrometer’s two analogue current outputs, select the current loop
scale
– (0 - 20 or 4 – 20 mA)—which matches that of the downstream
signal processing equipment (PLC, display device, controller, etc.). At
the pyrometer and at the controller, set the upper and lower limits of the
temperature range and the current loop output signal. Access this setting
using configuration layer
C010
.