KROHNE OPTISYS SLM 2100, Руководство пользователя, Страница: 13 / 88

DEVICE DESCRIPTION
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OPTISYS SLM 2100
www.krohne.com 01/2017 - 4002737304 - MA OPTISYS SLM 2100 R04 en
Display and keyboard
Display and keyboard are located in the front door of the electronics compartment. Display and
keyboard are based on the GDC (general device concept), which means a common HMI (human
machine interface) to all KROHNE GDC instruments is provided. The keyboard consists of four
membrane keys and the display is a LCD graphic display with a resolution of 128 x 64 Pixel.
Cable drum assembly and heater unit
The cable drum helps to move the sensor up and down in the basin. It is mounted directly on the
motor shaft of a synchronous motor, hidden behind the drum mounting plate. The cable drum
always moves with a very constant speed. Since the diameter of the cable roll in the drum varies,
the speed of the sensor varies. That is why the sensor moves slower during the end of the
sampling. Due to the roll design, shortening of cable or movement of the metal sleeve on the
sensor cable is prohibited. This will lead to different diameter of the cable roll and finally
resulting in wrong results in the height/depth measurements. The heater unit is located behind
the drum mounting plate. In combination with the fan the instrument maintains suitable
temperature conditions inside the enclosure of the meter.
Guide roller and zero point reference switch
The guide roller helps to keep the cable in place during the measuring process. A stable height
measurement is reached by zero point reference switch. The inductive proximity switch reacts
on the metal sleeve on the sensor cable and calibrates the home position. Each time when
leaving the menu the device performs a zero point calibration. In addition a regular calibration
during the process can be performed time based via the setup.
Sensor
The sensor used in the OPTISYS SLM 2100 is a suspended solid sensor. The sensor contains a
near-infrared light source and a receiver in an angle of 180
°
. Both are positioned in such a way
that the emitted near-infrared light has to pass through the liquid before reaching the receiver.
The suspended solids in the liquid absorb the emitted light leading to a lower intensity at the
detector. The light loss is proportional to the suspended solid content.
Pickup board & axle board
The pickup board is mounted on a spring loaded lever arm and transfers power and
communication signals to the cable drum.
The axle board on the cable drum is powered contactless ("inductively") by the pickup board. It
communicates with the main electronics unit via the pickup board and with the sensor via an
optical interface.
Cable feedthroughs
The 4 M20 cable feedthroughs are for the connection of power, signal and control cables. Only
three cable feedthroughs can be used, if the optional cleaning unit is installed.
Safety switch
The safety switch located on the top left corner of the cable drum compartment is a protective
device, which de-energizes the motor when the front door is opened in order to avoid danger due
to moving parts inside the meter.