Kett DT-8 User manual

Inline Iron Detector
DT-8
Operating Manual

1. Detection Principles and Features ……….......................... 4
2. Name and function of each part .................................... 5
3. Specifications ................................................................... 7
4. Setup …………………………................................................... 8
5. Sensitivity adjustment ........................................................ 13
6. Maintenance ................................................................... 1 4
CONTENTS

1-1. Detection Principles
This unit uses electromagnetic induction by a static magnetic field.
When a magnetic flux passes through a coil, a voltage will not be
generated in the coil unless there is no change in the magnetic flux.
However, if an iron piece enters this magnetic flux, the magnetic flux in
the coil changes due to magnetization of the iron piece and a voltage
will be generated in the coil eventually. This voltage will be produced by
the change in the magnetic flux to time and generated when the iron
piece is moving. Since magnets and coils are integrated in the sensor of
this unit, this unit will detect a generated voltage and notify of
presence/absence of an iron piece by sounding an alarm.
1-2. Features
● Figure of the principle
When there is no iron piece
Iron piece
Coil Coil
When there is an iron piece
● Block Diagram
Regulated power supply
Detector Amplifier Relay circuit
A C
External control
4
Magnet Magnet
Alarm unit
This unit is a device that detects a needle, bolt and iron piece mixed in a
woven fabric, non-woven fabric and an ore. By installing the sensor on a
belt conveyor line, conveyed products will continuously be inspected
and a mixed iron piece will be detected with high sensitivity.
1. Detection Principles and Features

2-1. Part names
＜1 channel ＞
＜2 channel s ＞
Alarm lumps for each channel (Small red)
＜3 channel s ＞
Alarm lumps for each channel (Small red)
Sensitivity adjustment knob
Reset switch
Power switch
Alarm lamp (Large red)
Pilot lamp
Hold switch
Sensitivity adjustment knobs
No.1 No.2
No.1 No.2
Sensor connectors for each channel
No.2 No.1 No.1 No.2
Fuse holder
Power connector
Buzzer connector
Sensor
connector
No.3 No.2 No.1 No.1 No.2 No.3
No.1 No.2 No.3
5
2. Name and function of each part
External control connector
Alarm lamp (Large red)
Pilot lamp
Sensitivity adjustment knob
Reset switch
Power switch
Hold switch
External control connector
Buzzer connector
No.1 No.2 No.3
Alarm lamp (Large red)
Pilot lamp
Sensor connectors for each channel
Power connector
Fuse holder
Fuse holder
Power connector
Buzzer connector
External control connector
Rear of the main unitFront of the main unit Sensor part
Rear of the main unitFront of the main unit Sensor part
Rear of the main unitFront of the main unit Sensor part
Reset switch
Power switch
Hold switch

＜4 channels ＞
2-2. Function of each part
PO WER Power switch Use to turn the power on and off.
P.L Pilot lump Lights up when the power is on.
SEN SE Sensitivity adjustment
knob
Adjustment of the detection sensitivity is available.
Alarm Alarm lamp and buzzer When a piece of iron is detected, it lights red and a buzzer is activated.
HOLD Hold switch This switch turns on the alarm lamp and
continuously activates the buzzer when a piece of
iron is detected.
RESET Reset switch Cancels the alarm lamp and buzzer continuous operation at the
time of detection.
No.1 No.2 No.3
No.4
No.4 No.3 No.2 No.1 No.1 No.2 No.3 No.4
6
N o . 1 N o . 2 N o . 3 N o . 4
N o . 1 N o . 2 N o . 3 N o . 4
Alarm lamp (Large red)
Pilot lamp
Sensitivity adjustment knobs Sensor connectors for each channel
Rear of the main unitFront of the main unit Sensor part
External control connector
Buzzer connector
Power connector
Fuse holder
Reset switch
Power switch
Hold switch
Alarm lumps for each channel (Small red)

7
Power supply
Power consumption
Detection type
Detection capability
Direction
Number of channels
Alarm function
External control
Accessories
Dimensions / weight
3. Specifications
：100 V AC (50/60 Hz) *(120V/200V/220V/240V) are optionally available
：10W per channel
：Magnetic induction method
：5 to 6 cm for insect pins (100 mg) at maximum sensitivity
：None
：1 to 4 *5 or more are optionally available
：Buzzer, lamp (large red) are shared action for all channels
Lamps (small red) are individual action for each channel
Two ways of continuous alarm and instant activation (selected with
hold switch)
：Contact circuit (non-voltage)
MAKE or BREAK (selected with hold switch interlocked with alarm)
：Power cable 2.5m
Sensor cable 5m (1 per channel)
External control cable 1m (0.75mm3, 4 cores)
Electronic buzzer (cable length 2.5m)
Spare fuse
Operating Manual
：400 (W) x 280 (D) x 250 (H) mm / 10Kg (1 channel type)
465 (W) x 305 (D) x 220 (H) mm / 15Kg (2/3/4 channels type)

Conveyor
To main unit
L-angle welded or bolted
4-1. Install
While referring to the figure below, install the main unit and sensor
according to "4-2. Main unit" and “4-3. Mounting the sensor”.
4-2. Main unit
Install in a dry place, paying attention to the following items.
(1) Tighten the connector firmly.
(2) Completely ground the main unit.
(3) ACV power supply should be taken from an outlet with little fluctuation.
Note) The best way of installation is to first perform temporary, perform normal
operation, and conduct tests in several locations before deciding.
Note) It is more effective to check the installation location regularly, not just at
the time of installation.
Installation of buzzer (with cable and connector)
Install the buzzer away from the sensor and sensor cable.
When the effective length is 3000mm or more
The sensor (detection part) may be distorted due to vibration or its
own weight. It is recommended to place a material other than metal
in the middle and install it as a support.
Example) When the detection surface faces upward
Support
8
4. Setup

4-3. Mounting the sensor
1. Mounting location
Select a location where there is no moving magnetic material (iron)
within 500 mm for sensor installation. For example, do not place
moving objects such as rotating rollers, chains, or gears, or electrical
devices or parts that emit magnetism, such as motors, electromagnetic
valves, and relays, as they may cause erroneous detection. Also, since
high voltage noise is generated when the fluorescent light is on, avoid
turning on the power of the fluorescent light during detection.
Note) These influences are also related to the direction of the sensor.
Note) If the object to be detected is expected to fall onto the sensor, attach
a non-magnetic protector.
2. Effects of vibration
Try to install it in a place where there is no vibration as much as
possible.
Note) Intermittent or irregular vibrations are more likely to cause false
detections than continuous vibrations, so avoid such locations.
3. Mounting direction
In order to reduce the burden on the sensor components, it is
recommended to install in the direction A shown in the figure below as
much as possible. If the sensor cannot be installed in direction A, install
it in direction B, and if it cannot be installed in direction B, install it in
direction C.
9

1 0
4. Mounting base
When fixing both ends of the sensor to the mounting base, the surfaces
of the mounting bases at both ends should be the same parallel plane
or the same horizontal plane.
This is to prevent the sensor itself from being distorted when the sensor
is fixed with bolts or the like.
5. Mounting frame
For the frame on which the sensor is installed, select a frame that can
withstand the vibration of conveyors and the weight of the sensor itself,
and that is either the main frame of the facility or a frame that is directly
connected to the main frame.
Note) If the sensor is installed on a separate frame from the main frame,
vibration of the main frame may cause false detection.
6. Materials of parts near the sensor
Since this instrument uses a static magnetic field generated by an
electromagnet, it is recommended that the parts near the sensor be
made of non-magnetic materials such as copper, aluminum, and
stainless steel rather than magnetic materials such as iron, nickel, and
chrome.
7. Electrical wiring and connectors
Do not place devices with large electric capacity, wiring of other electric
devices, or devices that are repeatedly turned on and off near the
sensor.
Also, do not bundle wires for other electrical devices and sensor cables,
but secure them separately. The sensor cable should be fixed to the
frame and the connector should be fully tightened.
Note) If the above is not followed, it may cause false detection.

4-4. External control
Omron MK2P contact relay is used inside the main unit as external
control circuit. Since the open/closed status of the contact point is
linked with alarm, it is possible to notify an external device of
detection of iron piece. When connecting an external device, use the
external control cable provided as accessory.
1 1
■Circuit schematic diagram
×
(RL)
(White)
(Green)
(Black)
(Red)
External control connector
（25φ 4P）
(Terminal number)
External control cable
■Contact capacity of RL (OMRON MK2P AC100V)
Input current (COSφ=0.4) :20A
Direct current :5A
Breaking capacity (COSφ=0.4)
Inductive load value :2A (for AC200V)
:1A (at AC400V)

4-5. Split sensor
The split sensor divides the inside of single sensor into 2 to 4 parts and
generates a voltage independently for each part. When a split sensor is
connected to a multi-channel main unit, not only the common large alarm
lamp but also the alarm lamp of the channel corresponding to the passage
position of mixed iron pieces will light up. This makes finding the iron
pieces easier.
CH1
Sensor・Single Iron piece
CH1 CH2
Sensor・split into 2
1 2
Iron piece
Main unit / 1 cannel type Main unit / 2 cannels type
CH1 CH2 CH3
Sensor / Split into 3 Iron piece
CH1 CH2 CH3 CH4
Sensor / Split into 4 Iron piece
Main unit / 3 cannels type Main unit / 4 cannels type
Alarm lump for each channel (Small red)
Alarm lump (Large red)
Lighting state
4-6. Sensor dimension diagram
4-20 holes
Effective width

1 3
■Optimization of sensitivity
Turning the sensitivity adjustment knob to the right increases the
ability to detect iron pieces, and turning it to the left decreases it. If
you increase the sensitivity, noise around the sensor will also be more
likely to enter, so adjust the sensitivity according to the installation
location, surrounding environment, measurement material, etc.
When detecting iron particles such as needles in products that
normally do not contain any iron, such as clothing and wood, Increase
the sensitivity.
When detecting iron particles mixed in magnetite or books, lower the
sensitivity to the extent that magnetite or binding wires are not
detected.
Note) If iron pieces are detected with the hold switch turned on, the alarm
lamp and buzzer will continue to operate. For the next detection,
remove the mixed piece of iron and press the reset button.
5. Sensitivity adjustment
（1）Make sure that the power supply, sensor and alarm buzzer are
properly connected.
（2）Turn on the hold switch.
（3）Adjust the sensitivity with the sensitivity adjustment knob while passing
the iron piece of the size you want to detect through the installed sensor.

1 4
（1）Dirt, dust, iron powder, etc. adhering to the sensor may cause
malfunction, so always keep it clean.
（2）The sensor connector part is vulnerable to tension, so handle it with care..
（3）For safe use of the device, prepare a "test piece" and check the operation
regularly or as needed.
5. Maintenance

d t - 8 _ m a n u a l _ e _ r e v 0 1 0 2 O C
Notes
● Copying some or all of the contents of this user manual without prior written consent is strictly prohibited.
● The contents of this user manual may be changed at any time in the future without any prior notice.
● The appearance and/or representations of the products and parts depicted in this user manual may
not appear exactly as their actual counterparts, but this does not affect their operation or functionality.
● This user manual was intended to be written as clearly and accurately as possible. However, if you are
unclear about anything in this user manual or notice any missing information, please contact us directly.
● We cannot be held responsible for any actions or effects resulting from the execution of any opera-
tions outlined in this user manual.