LumaSense Technologies ISR 12-LO - Handbuch (Seite 18)

IMPAC pyrometers ISR 12-LO · IGAR 12-LO
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Single storage: the single storage is used when you want to reset the stored value using an external im-
pulse via one contact closure from an external relay (i.e. between two measured objects). The relay contact
is connected directly to the pyrometer between pins J and K. This mode allows a new value to be estab-
lished, after each impulse from the reset signal.
double storage: when entering the reset intervals via push buttons or PC interface the double storage is
automatically selected. This mode utilizes two memories in which the highest measured value is held and is
deleted alternately in the time interval set (clear time). The other memory retains the maximum value
throughout the next time interval. The disadvantages of fluctuations in the display with the clock frequency
are thereby eliminated.
Note: The maximum value storage follows the function of adjustment of exposure time.
This results in:
• clear time ≤ the adjusted response time is useless
• clear times must be at least 3 times longer than the response time
• only maxima with full maximum value can be recorded, which
appear at least 3 times longer than the response time.
9.4
Operating mode (1 / 2 / M)
The series 12 pyrometers are designed for use in ratio mode. Additionally the pyrome-
ters can be used in two other modes:
In the mono mode the pyrometer only measures in one wavelength and the ratio mode
is off. In this case the operating mode is equivalent to a conventional 1-color pyrometer
(see 9.1, Emissivity).
The metal mode is a special mode which calculates the temperature combining the ratio and the 1-color
signal with an algorithm. The metal mode can be used to determine the temperature of metals and alloys
with unknown emissivity ratio (K). It should be used only for a short time to achieve a good approximation of
the object temperature if the temperature reading in 2-color or 1-color mode seems to be incorrect. After this
the pyrometer has to be switched back into 2-color mode and the temperature reading has to be corrected
with the adjustment of the emissivity slope K until the instrument shows the temperature determined in the
metal mode. A condition for the use of the metal mode are settings of
ε
= 1 and K = 1.
(Note: also the metal mode can be affected by the setting of the switch-off level, see 9.5)
9.5
Switch-off level (OFF / %)
The switch-off level is a function to avoid measuring errors caused by too low signals.
Ratio pyrometers are able to measure temperatures correctly even with very low sig-
nals, i.e. for example through a dirty viewing window or if dust exists in the field of view
or if the spot is not filled by the measuring object. If the signal is too low for a correct
measurement, the pyrometer interrupts the measurement and displays 1° below of beginning of the tempera-
ture range. Depending of the application the switch-off limit can be adjusted between 2 and 50%, ex works at
delivery set to 10%.
Note: The smaller the value the higher the chance that daylight or reflections affect a correct measurement.
9.6
Analog output (0 / 4 mA)
The analog output has to be selected according to the signal input of the connected
instrument (controller, PLC, etc.).
9.7
Setting of subrange (from / to)
You have the opportunity to choose a subrange (minimum 51°C) within the basic measuring range of the
pyrometer. This subrange corresponds to the analog output. “from“ describes the beginning of this measur-
ing range, “to“ the end of the range.
Additionally with the setting of a subrange it is possible to fulfill the requirements of the “auto” clear mode of
the maximum value storage (see 9.3).
Settings:
mono mode
ratio mode
metal mode
Settings:
2%
.
.
.
50%
Settings:
0 ... 20 mA
4 ... 20 mA