INFRATHERM pyrometer ISR 50-LO
41
8.1.1
Test current
The diagnostic push button „TEST“ generates a current on the analog output which is used to check
if a connected external indicator shows the correct temperature value. The test current output is
centered to the chosen analog output span, consequently 10 mA is supplied if the analog output is
adjusted to 0 - 20 mA and 12 mA is supplied if the analog output span is set from 4 - 20 mA. The LC
display indicates the respective current along with the corresponding temperature. For example if a measur-
ing range of 800°C to 2500 °C is selected the temperature shown in the display is 1650°C). This temperature
must be reflected exactly by the indicator which is supplied by the respective current. If this is not the case
the selected analog input current span of the indicator is not equivalent to the chosen current output span of
the pyrometer and one of the current spans or temperature range have to be modified. By pressing the
„TEST“ push button once again or by pressing any other push button, the test current is switched off. Also
after 1 minute idle time the “TEST” current is switched off. The unit will be in the measurement mode again.
8.1.2
Interface switch
With the interface switch the interface operation mode RS232 or RS485 can be
selected. Changing the interface via the serial interface is not possible.
8.2
Factory settings
Operating mode (MONO / RATIO) = RATIO
Emissivity slope (
ε
1
/ε
2
) = 1.000
Emissivity (
ε
) = 1.000
Exposure time (t
90
) = min.
Clear time (t
Clear
) = off
Analog output (0...20 / 4…20 mA) = 0...20 mA
Sub range (from / to) is basic temperature range
Switch-off limit (Intens Min) = 10%
Warning level „dirty window“ = 0% (= “off”)
Adress (Adr) = 00
Baud rate (kBaud) = 19.2 kBd
Wait time (tw) (for RS485) = 10
Temperature display (°C / °F) = °C
Switch for interface (RS485 / RS232) = RS232
9
Parameters / settings
9.1
Operating mode (Mode)
The standard use for the ISR 50-LO is as a ratio pyrometer (setting RATIO). Addition-
ally the pyrometer can be switched to 1-color mode and used like a conventional py-
rometer in the spectral range near 0.9 µm (setting MONO).
9.1.1
Emissivity slope K =
ε
1
/
ε
2
Note:
A setting of the emissivity slope K =
ε
1
/
ε
2
is only possible in ratio mode.
In ratio mode (2-color mode) the pyrometer is measuring simultaneously with 2 sensors
in adjacent wavelengths. It calculates the temperature by ratioing the radiation intensi-
ties of the two wavelengths. This ratio technique eliminates a number of factors that
degrade the accuracy of a conventional single color instrument e.g. measurement inde-
pendent of emissivity in wide areas, unaffected by dust in the field of view, unaffected by dirty viewing win-
dows or lenses, etc. In some cases the emissivities of the two wavelengths can differ so that it is necessary
to correct the ratio of the two emissivities (
ε
1
/
ε
2
) to get a correct temperature reading. This correction can
be done with the emissivity slope setting K. The K-factors of metals are normally higher than 1. For a correct
measuring result it is recommended to make a comparison test, e.g. with a thermocouple probe. Then the K-
factor has to be corrected until the pyrometer shows the same temperature value.
If the operating mode „RATIO“ is selected, additionally to the current
temperature the display shows the emissivity slope. Then the emis-
sivity slope can directly be changed via the and keys, the effect
to the measuring temperature can be observed immediately. Upon
completion the settings, the value must be taken over with “Enter”.
Settings:
RATIO
MONO
Settings:
0.800
.
.
.
1.200
Emissivity
slope K
