Rkc LT1 User Manual
A
Back Pressure Type Level Switch
!
LT1
Instruction Manual
IMR01C13-E1
Thank you for purchasing this RKC product. In order to
achieve maximum performance and ensure proper operation
of your new instrument, carefully read all the instructions in
this manual. Please place the manual in a convenient
location for easy reference.
SYMBOLS
WARNING
CAUTION
To prevent injury to persons, damage to instrument
and equipment, a suitable external protection device
shall be required.
All wiring must be completed before power is turned
on to prevent electric shock, fire or damage to
instrument and equipment.
This instrument must be used in accordance with the
specifications to prevent fire or damage to
instrument and equipment.
This instrument is not intended for use in locations
subject to flammable or explosive gases.
Do not touch high-voltage connections such as
power supply terminals, etc. to avoid electric shock.
RKC is not responsible if this instrument is repaired,
modified or disassembled by other than
factory-approved personnel. Malfunction can occur
and warranty is void under these conditions.
: This mark indicates precautions that must be
taken if there is danger of electric shock, fire,
etc., which could result in loss of life or injury.
: This mark indicates that if these precautions
and operating procedures are not taken,
damage to the instrument may result.
: This mark indicates that all precautions should
!
be taken for safe usage.
: This mark indicates important information on
installation, handling and operating
procedures.
: This mark indicates supplemental information
on installation, handling and operating
procedures.
: This mark indicates where additional
information may be located.
WARNING
This product is intended for use with industrial machines,
test and measuring equipment.
(It is not designed for use with medical equipment and
nuclear energy.)
This is a Class A instrument. In a domestic environment,
this instrument may cause radio interference, in which
case the user may be required to take additional
measures.
Be sure to provide an appropriate surge control circuit
respectively for the following:
If input/output or signal lines within the building are
longer than 30 meters.
If input/output or signal lines leave the building,
regardless the length.
This instrument is protected from electric shock by
reinforced insulation. Provide reinforced insulation between
the wire for the input signal and the wires for instrument
power supply, source of power and loads.
All precautions described in this manual should be taken to
avoid damage to the instrument or equipment.
All wiring must be in accordance with local codes and
regulations.
All wiring must be completed before power is turned on to
prevent electric shock, instrument failure, or incorrect
action.
To prevent instrument damage as a result of failure, protect
the power line and the input/output lines from high currents
with a suitable overcurrent protection device with adequate
breaking capacity such as a fuse, circuit breaker, etc.
Prevent metal fragments or lead wire scraps from falling
inside instrument case to avoid electric shock, fire or
malfunction.
T ighten each terminal screw to the specified torque found
in the manual to avoid electric shock, fire or malfunction.
For proper operation of this instrument, provide adequate
ventilation for heat dispensation.
Do not connect wires to unused terminals as this will
interfere with proper operation of the instrument.
Turn off the power supply before cleaning the instrument.
Do not use a volatile solvent such as paint thinner to clean
the instrument. Deformation or discoloration will occur. Use
a soft, dry cloth to remove stains from the instrument.
If this instrument is applied with strong impact, its
characteristic change may result. Therefore, do not drop it
nor apply the impact to it.
This instrument is intended for the level measurement of
liquids used in semiconductor cleaning equipment. The
instrument has been successfully used to measure the
liquids indicated below. Please note that if the surface
tension or specific gravity changes due to the heat of
reaction of the liquid or other reason, incorrect detection
may result. The instrument has not been tested for use
with liquids other than those indicated below. If you wish to
use the instrument with other liquids, please test prior to
use.
Relevant liquids
Pure-water 72 1
Hydrochloric acid 72 1.19
Ethanol 22 0.79
Isopropyl alcohol (IPA) 21 0.79
This instrument detects a change in pressure within a
measuring tube inserted into a measured liquid. Leakag e
of the gas thorough the tube connection may cause a
detection error. Therefore, correctly connect the tube.
In addition, be careful that incorrect detection may result if
used in one of the following conditions:
when there are rapid liquid level cha nges,
when there are pressure changes and/or air stream in
the measuring tank, or
when a closed tank is used for level measurement.
CAUTION
Surface tension
(mN/m)
(Continued on the next page.)
Gravity
ll Rights Reserved, Copyright 2013, RKC INSTRUMENT INC.
RKC INSTRUMENT INC.
®
(Continued from the previous page.)
Do not fully close the measuring tube connecting section. If
so, the built-in very low pressure sensor may be damaged.
Use the back pressure purge gas (input media pressure) at
a constant pressure of 20 to 49 kPa. If a pressure of more
than 49 kPa is directly applied to the LT1, the instrument
may fail.
This instrument uses the pressure inside the unit as a
reference pressure. Detection and operation occur when
the pressure at the measurement side changes with
respect to the pressure inside the unit. Even when there is
no liquid (no change in the pressure at the measurement
side), changes in the ambient pressure of the installation
location may cause false detection. Exercise caution to
avoid changes in the ambient pressure, such as opening
and closing the cover of the instrument.
To prevent backflow of the measured liquid, set the purge
pressure higher than the maximum value of input pressure.
Input pressure:
The pressure that is applied at the end of the
measuring tube.
When applying back pressure, use nitrogen gas of high
purity which does not contaminate the liquid.
When problem in particular does not have liquid pollution
by purge gas, use air or the nitrogen gas which removed
garbage and oil content of 0.3 m greater or equal.
Nitrogen gas used for the application of ba ck pressure is
resistant against corrosion and also for preventing
backward flow. As a semiconductor pressure element is
used in the detector of this instrument, the detector may be
damaged if exposed to corrosive gas or liquid.
If gas bubble forming affects product quality, etc., use a
duplex tube so that they may be exhausted to the
atmosphere along the inner surface of the tube.
Do not disconnect the tube for purge gas input with the
liquid filled in the tank. If disconnected under the above
condition, the liquid may flow backward.
Before stopping the supply of nitrogen gas, wash the tank
and also clear away the corrosive atmosphere.
T o heighten antinoise characteristics, the orifice section is
connected to the instrument internal circuit (shield). When
connecting a metal piping connector, conduct insulation
treatment, it necessary.
This instrument is not clean pack product.
NOTICE
This manual assumes that the reader has a fundamental
knowledge of the principles of electricity, process control,
computer technology and communications.
The figures, diagrams and numeric values used in this
manual are only for purpose of illustration.
RKC is not responsible for any damage or injury that is
caused as a result of using this instrument, instrument
failure or indirect damage.
RKC is not responsible for any damage and/or injury
resulting from the use of instruments made by imitating this
instrument.
Periodic maintenance is required for safe and proper
operation of this instrument. Some components have a
limited service life, or characteristics that change over time.
Every effort has been made to ensure accuracy of all
information contained herein. RKC makes no warranty
expressed or implied, with respect to the accuracy of the
information. The information in this manual is subject to
change without prior notice.
No portion of this document may be reprinted, modified,
copied, transmitted, digitized, stored, processed or
retrieved through any mechanical, electronic, optical or
other means without prior written approval from RKC.
1. CHECKING THE PRODUCTS
The LT1 detects a liquid level by a change in b ackpressure
and then outputs a control signal through relay contacts. As
the LT1 has a built-in orifice, it can automatically attain the
rated purge flow (input media consumption) only by
supplying the gas of 20 kPa.
Before using this product, check each of the following:
Model code
Check that all of the items delivered are complete.
Check that there are no scratch or breakage in external
appearance (case, front panel, terminal, etc.).
Model code
LT1 - N N /
(1) (2) (3) (4)
(1) Relay output type
A: Energized
The relay is in the energized state with the output
turned on.
B: De-energized
The relay is in the energized state with the output
turned off.
(2) Connection type
N: Single connection type
(3) Extremely small pressure detecting function
N: No function
(4) Specifications
A: High sensitivit y specification
B: Low sensitivity specification
Accessories
Instruction Manual (IMR01C13-E1) .................... 1 copy
Mounting screw (M3 6) .................................... 4 pieces
If any of the products are missing, damaged, or if
your manual is incomplete, please contact RKC sales
office or the agent.
2. PARTS DESCTIPTION
(1)
(2)
(3)
(4)
(5)
(1) Terminals
Power supply and output terminals.
(2) Output lamp [Green]
Lights when the output is turned on.
(3) Power lamp [Green]
Lights when the power is turned on.
(4) Measuring tube connecting section [P. OUT]
Connect the tube for measuring.
(5)
Purge gas input tube connecting section [P. IN]
Connect the tube for purge gas input.
OUT
POWER
P. OUT
P. IN
2
IMR01C13-E1
Loading...