User Manual

K7L-U@/-UD@@
14
Nomenclature and DIP Switch Settings
Noise Countermeasures (Common)
Noise Canceller Function for Highly Sensitive Impedance
Detection
The K7L-U/UB Liquid Leakage Sensor Amplifier detects liquids with
impedance as high as 1 MW and connects to the Sensing Band
through a cable that can be extended up to 400 meters.
Countermeasures against external noise are especially important for
the Sensing Band and connecting cable because they pick up
external noise like an antenna. The K7L incorporates the noise
canceller function described below.
Connected with 3-conductor Cable that Offsets Inductive
Noise (Patent Pending)
A VCT cable with three conductors (lines) is used as shown in the
diagram. Line 1 is connected to the Sensing Band and line 2 is left
open. Lines 1 and 2 are almost in the same position and thus will
experience the same noise level. The K7L detects the difference
between these signals (including noise). This means that the noise
signals in lines 1 and 2 are offset against each other and a reading for
the signal, without inductive noise, can be made.
Power indicator (green)
(Lit when power is supplied.)
Output indicator (red)
(Lit when output is ON.)
Resistance adjuster
Power indicator (green)
(Lit when power is supplied.)
Output indicator (red)
(Lit when output is ON.)
Resistance
adjuster
K7L-U/UD/UDP
K7L-UB/UDB/UDPB
Sensing Range Settings
* Disconnection detection is supported only by the
K7L-UD/UDB/UDP/UDPB.
DIP switch Output
Output is OFF when liquid leakage
or disconnection is detected. *
Output is ON when liquid leakage
or disconnection is detected. *
4
2
3
Sensing
Band
Signal transmission
line
Line 1
Line 2
Connecting cable
Signal
transmission circuit
Subtraction circuit
Resistance
measurement circuit
K7L