WM:PD4000329
SINGLE POINT BEAM LOAD CELL
1. INTRODUCTION
The LCB04 series single point beam load cells are compact (150 mm
length, 34 mm height) and low cost, optimum as platforms for from ordi-
nary weighing to platforms for mixing and filling. Being of a single point
design allows for simplified weighing system construction.
To install the load cell properly, the static conditions, as well as dynamic
factors (i.e., shock and vibration) must be considered.
To obtain the best performance from the load cell, read this instruction
manual before installation.
2. SPECIFICATIONS
Rated output ............................................................................... 2mV/V 10%
Maximum safe overload............................................ 150% of rated capacity
Combined error ........................................................... 0.02% of rated output
Zero balance................................................................... 5% of rated output
Compensated temperature range............................................ -10 to 40
Maximum excitation voltage...................................................................... 15V
Input terminal resistance.............................................................. 420 30
Output terminal resistance ............................................................. 350 5
Insulation resistance ...........................................2000M or over at 50VDC
Temperature effect on zero ..............................0.023% of rated output/ 10
Temperature effect on span ...................................... 0.014% of LOAD/ 10
Cable thickness/length ................................................................ 3.5 1.5m
Maximum loading area ................................................... 400 mm 400 mm
Maximum moment ((Rated capacities) X 100 N cm Only 250L 18kN cm
)
3. NOTES ON INSTALLATION
NOTE
Use care not to damage the resin coating of the load cell. When
installing, do not apply excessive load to the load cell.
3-1 INSTALLING ON A BASE
(1) The base should be rigid to prevent it from slanting or curving under
normal operating conditions.
If the base yields, the platform will bend and adversely affect the load
cell.
(2) Insert a spacer of 2 mm or greater between the load cell and the base.
(3) Use a highly rigid base. The mounting surface for the load cell and the
spacer requires a surface finish of at least 25 mRa (JIS*).
*JIS=Japan Industrial Standard
(4) Use hexagon socket head bolts (tensile strength Class 10.9-JIS or over)
or high-tension hexagon head bolts (tensile strength Class 10.9-JIS or
over) to attach the load cell on the base. Table 1 shows the applicable
clamping torque. Be sure to avoid using ordinary bolts (of a lower tensile
strength) available on the market.
Table 1
(5) Make sure that the attaching surface is clean and free from foreign matter.
Tighten the bolts while holding the securing end of the load cell.
3-2 ATTACHING THE PLATFORM
(1) The tare and the platform should be as light as possible to prolong the
service life and excellent performance of the load cell.
(2) Insert a spacer with 2 mm or greater between the load cell and the
platform.
(3) Use a platform fixture with high rigidity. The mounting surface for the
load cell and the spacer requires a surface finish of 25 mRa (JIS*) or
less.
(4) Use hexagon socket head bolts (tensile strength Class 10.9-JIS or over)
or high-tension hexagon head bolts (tensile strength Class 10.9-JIS or
over) to attach the platform fixture to the load cell. Table 1 shows the
applicable clamping torque. Avoid using ordinary bolts (of low tensile
strength) available on the market.
(5) Make sure that the attaching surface is clean and free from foreign matter.
Tighten the bolts while using much care not to apply unnecessary force
(torsion or lateral load) to the load cell.
3-3 OVERLOAD PRECAUTIONS
(1) Mechanical strength of the load cell
When a load is applied to the center of the load cell, a load of less than
150% of the rated capacity will not cause any trouble.
However, the allowance range of the overload is reduced as the loading
point shifts from the center of the load cell. Therefore, the allowable limit at
the corner load points of the platform should be 100% of the rated capacity.
Repeated overloading, exceeding the allowable limit, may shorten the service
life of the load cell, and may even destroy it in extreme cases.
Where there is a possibility that a load may exceed the allowable limit,
attach an overload stopper to protect the load cell as described below.
(2) Overload stopper
If excessive shock is applied when position-
ing an object on the platform, the load may
exceed the allowable limit. Therefore, be sure
to attach an overload stopper just below the
load end of the load cell.
[Recommended installation]
Attach the overload stopper so that the
stopper comes into contact with the load cell
with as wide an area as possible when 150%
of measurement load plus the platform weight
(Here after referred to as F.S. ).
(See Figure 2.)
(3) Corner stopper
Although the overload stopper is properly ad-
justed, if an overload is applied to the corners of
the platform, it may exceed the allowable limit
due to the flexibility of the base. Therefore, be
sure to attach corner stoppers.
[Recommended installation]
Attach the corner stoppers so that the stoppers
come into contact with the bottom of the
weighing platform with as wide an area as
possible when 100% of F.S. is applied to each
the four corners of the platform.
(See Figure 3.)
(4) If an overload or excessive shock force is likely to occur, overlay the platform
with a shock absorbing pad or select a load cell with a rated capacity that
is double or triple the F.S. value.
(5) If a moment greater than the specified maximum value is applied to the
center of the load cell, the load cell may not function properly. Especially
when the load is over one-half of the rated capacity, it may cause the
moment to exceed the specified maximum value, even within the maximum
loading area. Under such a condition, place the center of the load on the
platform directly above the center of the loading area so that the maximum
moment will not be exceeded.
The moment applied to the load cell can be obtained as follows:
(Moment[N cm])=(Distance from the center of gravity of the object to the
load cell center[cm]) (mass of the object[kg]) 10
3-4 CABLE COLOR CODE / TREMINAL TYPE
RED ............ EXC + WHITE ................EXC -
GREEN ....... SIG + BLUE ..................SIG -
YELLOW ..... SHIELD
4. MAINTENANCE
(1) Remove all dirt and dust from the load cell, and always use it in a clean
environment.
(2) Use a blower to clean the load cell. Do not wash using water.
(3) Periodically inspect the overload stopper and corner stoppers.
5. DIMENSION
(6) For the allowable dimensions of the platform, see Figure 1. Also, when
designing a platform, see the "3-3 OVERLOAD PRECAUTIONS" .
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