Overview
ENG_131840.XML
P_WT01_XX_00414
Siemens offers load cells in the SIWAREX WL200 series. All load cells are equipped with strain gauges. They are used for static and dynamic weight measurements.
The wide range of different designs available enables SIWAREX load cells to be used in a variety of applications: from single point load cells to bending and shear beams, up to S-type, compression and ring-torsion load cells.
The different load cell series cover rated load ranges from 0.3 kg (0.66 lb) to 500 t (492.10 tn. l.).
The variety of modules available and their characteristics, including:
• predominantly stainless steel for high anti-corrosion protection
• predominantly hermetically sealed housing enabling use even in hostile or corrosive environments
• compact frame sizes for easy installation
make SIWAREX load cells suitable for virtually all applications in industrial weighing, e.g. hopper scales and bin weighing equipment, platform scales, vehicle scales, hybrid weighing machines etc.
Almost all series have been approved for use with Class III weighing machines requiring official calibration in accordance with EN 45501 and conform to OIML R60.
Of course, load cells can also be supplied for other rated loads, higher accuracy, and/or Ex approval, depending on requirements.
Application
ENG_842533.XML
Single point load cells
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Type
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Rated load
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Accuracy class
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Applications
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Material
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SIWAREX WL260 SP-S AA
P_WT01_XX_00406
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3 ... 100 kg (6.61 ... 220.46 lb)
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- Small platform scales with one load cell
- Small belt scales
- Class III weighing machines
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Aluminum
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SIWAREX WL260 SP-S AB
P_WT01_XX_00407
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50 ... 500 kg (110.23 ... 1 102.31 lb)
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- Small to medium-size platform scales with one load cell
- Belt scales
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Aluminum
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SIWAREX WL260 SP-S AE
P_WT01_XX_00457
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0.3 ... 3 kg (0.66 ... 6.61 lb)
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- Miniature loads and high-resolution scales
- Small belt scales
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Aluminum
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SIWAREX WL260 SP-S SA
P_WT01_XX_00408
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5 ... 200 kg (11.02 ... 440.92 lb)
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- Small to medium-size platform scales with one load cell
- Small belt scales
- Class III weighing machines
- Available with or without explosion protection
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Stainless steel EN 1.4542
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SIWAREX WL260 SP-S SB
P_WT01_XX_00449
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6 ... 60 kg (13.23 ... 132.28 lb)
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- Small platform scales
- Small belt scales
- Class III weighing machines
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Stainless steel EN 1.4542
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SIWAREX WL260 SP-S SC
P_WT01_XX_00450
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10 ... 500 kg (22.05 ... 1 102.31 lb)
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- C3
- C3 MR
- C4 MR (high-precision)
- Legal-for-trade
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- Platform scales
- Belt scales
- Class III weighing machines
- Suitable for food and beverages industry, or pharmaceuticals.
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Stainless steel EN 1.4542
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1) Available in C4 with Y = 20 000 upon request.
2) SIWAREX WL260 SP-S AB is not approved for legal-for-trade operation.
Bending beam load cells
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Type
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Rated load
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Accuracy class
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Applications
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Material
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SIWAREX WL230 BB-S SA
P_WT01_XX_00403
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10 ... 500 kg (22.05 ... 1 102.3 lb)
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- Small hopper and platform scales
- Class III medium accuracy weighing machines
- Available with or without explosion protection
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Stainless steel EN 1.4542
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Shear beam load cells
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Type
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Rated load
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Accuracy class
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Applications
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Material
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SIWAREX WL230 SB-S SA
P_WT01_XX_00404
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500 kg ... 5 t (1 102.31 lb ... 4.92 tn. l.)
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- Hopper, overhead rail and platform scales
- Available with or without explosion protection
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Stainless steel EN 1.4542
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SIWAREX WL230 SB-S CA
P_WT01_XX_00464
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100 kg ... 10 t (220.46 lb ... 9.84 tn. l.)3)
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- Platform scales
- Hopper scales
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Nickel-plated steel
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3) The 100 kg and 250 kg load classes are bending beams.
Double shear beam load cells
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Type
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Rated load
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Accuracy class
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Applications
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Material
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SIWAREX WL290 DB-S CA
P_WT01_XX_00470
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2.3 ... 113 t (2.26 ... 111.22 tn. l.)
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- Large platform and hopper scales
- Scales in vehicles
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Nickel-plated steel
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S-type load cells
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Type
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Rated load
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Accuracy class
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Applications
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Material
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SIWAREX WL250 ST-S SA
P_WT01_XX_00405
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50 kg ... 10 t (110.23 lb ... 9.84 tn. l.)
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- Voltage and pressure applications
- Suspended scales
- Hopper scales
- Hybrid weighing machines
- Available with or without explosion protection
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Stainless steel EN 1.4542
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Compression load cells
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Type
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Rated load
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Accuracy class
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Applications
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Material
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SIWAREX WL270 CP-S SA
P_WT01_XX_00409
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500 kg, 50 t (1 102.3 lb, 49.21 tn. l.)
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- Vehicle scales
- Overhead rail scales
- Hopper scales
- Available with or without explosion protection
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Stainless steel EN 1.4542
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SIWAREX WL270 CP-S SB
P_WT01_XX_00410
|
100 t (98.42 tn. l.)
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- Hopper scales
- Bin weighing equipment
- Vehicle scales
- Available with or without explosion protection
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Stainless steel EN 1.4542
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SIWAREX WL270 K-S CA
P_WT01_XX_00424
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2.8 ... 500 t (2.76 ... 492.10 tn. l.)
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- Hopper scales
- Bin weighing equipment
- For high temperature range (optional)
- With double bridge (optional)
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Painted steel
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Ring torsion load cells
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Type
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Rated load
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Accuracy class
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Applications
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Material
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SIWAREX WL280 RN-S SA
P_WT01_XX_00425
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60 kg ... 60 t (132.28 lb ... 59.05 tn. l.)
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- Hopper, belt, platform and roller table scales
- Available with or without explosion protection
- Low mounting height
- Integrated overload protection (up to 13 t rated load)
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Stainless steel EN 1.4542
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Design
ENG_131847.XML
Load cells are sensors that convert a mechanical variable (i.e. weight) into an electrical signal, usually a voltage.
They work according to different measuring principles. Siemens SIWAREX WL200 load cells utilize so-called strain gauges. These are specially formed electrical conductors which are insulated by means of a suitable material. The strain gauges are attached to the basic element, a specially formed spring body, by friction locking.
Under the influence of a weight force F, the spring body is deformed (see schematic presentation) and as a result the strain gauge deforms elastically. Due to the change in the external shape of the strain gauge, the ohmic resistance of its conductor also changes. The top left and bottom right strain gauges are compressed, their resistance films are shortened and the ohmic resistance is reduced accordingly. The top right and bottom left strain gauges are stretched, their resistance films are extended and the ohmic resistance is increased.
For each load cell, at least four strain gauges are connected together to form a complete Wheatstone bridge. The stretched or compressed strain gauges are connected so that the positive or negative resistance changes are added together to form a total imbalance in the bridge.
On one bridge diagonal, the power voltage is applied (with 6-conductor technique, also the sensor voltage, SENSE) and on the other diagonal, the measured voltage is tapped.
With a constant power voltage (EXC), the measured voltage (SIG) changes proportionally to the introduced load.
G_WT01_XX_10090
Principle of a bending beam load cell, loaded
G_WT01_XX_10091
Principle of a Wheatstone bridge
