Zemic can offer several load cell models with ATEX certificates. You can find the ATEX certificates here.

Yes, the max sensitivity of usable loadcells is +/- 7mV/V.

By using a junction box you can connect more loadcells  to one device.

Please contact one of our representatives. The contact information can be found here.

The Zemic Europe naming system can be found here. 

The accuracy of the load cells is stated on the Zemic Europe datasheet which can be found on this website. 

When connecting a 6-wire load cell to a 4-wire connector, the sense wires should be connected in the same place as the excitation wires.

The Sense + wire should be installed together with the Excitation + wire into the Excitation + connection.
The Sense – wire should be installed together with the Excitation – wire into the Excitation – connection.

Please look at the picture below for this solution in practice as (Please note this is an example):

When connecting a 4-wire load cell to a 6-wire connector, two bridge wires are necessary to connect the wires properly.

These bridge wires should be connected between the Excitation + and the Sense +.
The other wire between the Excitation - and the Sense -.

Please look at the picture below for this solution in practice. Please note this is an example.

Zemic Europe uses several different stainless steels in their products. Zemic Europe uses austenitic stainless steel which is not magnetic. When austenitic steel is heat treated it turns into martensitic stainless steel which is semi-magnetic and that can give a magnetic effect. 

Ingress Protection is the degree of protection the load cell provides against intrusion of dust and water. The degree of protection can be found at the datasheet of every load cell model. All Zemic Europe models are completely protected against dust ingress and are therefore classified as IP6X

An explanation of the IP classification located at X can be found in the next table:

LOAD CELL TROUBLESHOOTING

                                                                                                                                                                 Get your replacement       

INTRODUCTION

Load cells are designed to sense force or weight under a wide range of adverse conditions; they are not only the most essential part of an electronic weighing system, but also the most vulnerable.
Load cells might be damaged because of (shock) overloading, lightning strikes or heavy electrical surges in general, chemical or moisture ingress, mishandling (dropping, lifting on cable, etc.), vibration or internal component malfunction. As a direct result the scale or system might (zero) drift, provide unstable / unreliable readings or not register at all.
This application note is written to assist users with potential load cell problems. It describes basic field tests which can be performed on site*, and provides the information necessary to interpret the results.
*Proper field evaluation is absolutely critical to prevent similarly induced damage in the future! Under no circumstances should fault location, as described below, be attempted on load cells installed in a hazardous area!

IN GENERAL

Carefully check the system integrity before evaluating the load cells:
- check for force shunts (might be caused by dirt, mechanical misalignment or accompanying components such as stay- or check rods.
- check for damage, corrosion or significant wear in the areas of load introduc¬tion.
- check cable connections to junction box and indicator.
- check the measuring device or indicator with an accurate load cell simulator.
Visually inspect the load cells before performing the tests as described on the following pages. Pay particular attention to signs of corrosion (especially around the critical gauge area), the integrity of the cable (might be compromised due to cuts, abrasions, etc) and the condition of the cable entry.

The following test equipment is required to properly evaluate a load cell:
- A high quality, calibrated, digital volt- and ohmmeter with a measuring accuracy of ≤0.5Ω and ≤0.1 mV, to measure the zero balance and integrity of the bridge circuit.
- A megohm meter*, capable of reading 1000 Mohms with a resolution of 1 MΩ at 50 volts DC, to measure the insulation resistance.
*Do not use megohm meters which supply more than 50 volts to the load cell, in order to prevent permanent damage!
- Or use a portable multifunctional calog hand held tester.
- A means to lift the dead load (weighbridge, tank, hopper, conveyor, etc.) off the load cell to be able to measure the zero balance or to remove the load cell(s), i.e. a crane, hydraulic jack, etc.

Load cells are produced according to specifications and tolerances which are described in the applicable data sheet. More detailed information can be found on the calibration sheet which is packed with each load cell. The calibration sheet mentions the exact values for the input and output resistance, insulation resistance, zero balance, rated output and the correct wiring code; it provides an important reference for the values which can be measured and should be filed with the system documentation set.

TEST PROCEDURES AND ANALYSIS

The diagram below represents a proposed sequence for testing load cells after a particular system malfunction. Isolate the fault location by moving a relatively small deadweight over each load cell, or by disconnecting load cell by load cell.

TEST #1: ZERO BALANCE

The Zero Balance is defined as the load cell output in a "no-load" situation. Therefore, all weight (including deadload) has to be removed from the load cell. Low capacity load cells should be measured in the position in which the load cell is designed to measure force to prevent the weight of the element giving wrong results.
The load cell should be connected to a stable power supply, preferably a load cell indicator with an excitation voltage of at least 10 volts. Disconnect any other load cell for multiple load cell systems.
Measure the voltage across the load cell's output leads with a millivoltmeter and divide this value by the input or excitation voltage to obtain the Zero Balance in mV/V. Compare the Zero balance to the original load cell calibration certificate ( if available ) or to the data sheet.

ANALYSIS

Changes in Zero Balance usually occur if the load cell has been permanently deformed by overloading and/or excessive shocks. Load cells that experience progressive zero output changes per time period are most likely undergoing a change in the strain gauge resistance because of chemical or moisture intrusion. However, in this case the insulation resistance and/or the bridge integrity will also be compromised.

TEST #2: INSULATION RESISTANCE

The insulation resistance is measured between the load cell circuit and element or cable shield. Disconnect the load cell from the junction box or indicator and connect all input, output and sense (if applicable) leads together.
Measure the insulation resistance with a megohmmeter* between these four or six connected leads and the load cell body. Repeat the measurement between the same 4 or 6 leads and the cable shield. Finally measure the insulation resistance between the load cell body and cable shield.
*Never use a Megohmmeter to measure the input or output resistance, as it normally operates at a voltage which exceeds the maximum excitation voltage by far!
* If shield is connected to load cell body please skip housing / screen insulation test.

ANALYSIS

The insulation resistance of all load cells should be 5000 megohms or more for bridge circuit to housing, bridge circuit to cable screen and load cell body to cable screen.
A lower value indicates electrical leakage, which is usually caused by moisture or chemical contaminations within the load cell or cable. Extremely low values (< 1kΩ ) indicate a short circuit rather than moisture ingress.
Electrical leakage results usually in unstable load cell or scale reading output. The stability might vary with temperature.

TEST #3: BRIDGE INTEGRITY

The bridge integrity is verified by measuring the input and output resistance as well as the bridge balance. Disconnect the load cell from the junction box or measuring device.
The input and output resistance is measured with an ohmmeter across each pair of input and output leads. Compare the input and output resistance to the original calibration certificate ( if available ) or to the data sheet specifications.
The bridge balance is obtained by comparing the resistance from -output to -input, and -output to +input. The difference between both values should be ≤ 1Ω.

ANALYSIS

Changes in bridge resistance or bridge balance are most often caused by a broken or burned wire, an electrical component failure or internal short circuit. This might result from over-voltage ( lightning or welding ), physical damage from shock, vibration or fatigue or excessive temperature.

TEST #4: SHOCK RESISTANCE

The load cell should be connected to a stable power supply, preferably a load cell indicator with an excitation voltage of at least 10 volts. Disconnect all other load cells for multiple load cell systems.
With a voltmeter connected to the output leads, lightly rap on the load cell with a small mallet to mildly shock it. Exercise extreme care not to overload low capacity load cells while testing their shock resistance.
Watch the readings during the test. The readings should not become erratic, should remain reasonably stable and return to original zero readings.

ANALYSIS

Erratic readings may indicate a failed electrical connection or a damaged glue layer between strain gauge and element as a result of an electrical transient.

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OIML is an intergovernmental treaty organization which makes international regulations, standards and related documents. In this way, trade barriers and cost in a global market can be reduced. An OIML certification is given to a load cell when this particular model is conform these international regulations. When a load cell is OIML approved it can be used in an CE verified applications.

Yes, Zemic Europe can make a  custom made load cell for your application. Please keep in mind that a minimum order quantity might be required.

Yes, Zemic Europe has most load cell models available in STEP format. These 3D files can be downloaded from the Zemic Europe website. When the required model is not available on the website please contact us.

Yes, it will. However, there is a difference between load cells with 4-wire and 6-wire connection. 6-wire load cells will still conform the calibration certificate which is delivered with it when they are connected as 6-wire load cells. The 4-wire load cells might have different values from the calibration certificate. 

When the cutting of the cable is necessary or can’t be avoided, please make sure to cut all cables to equal length.

All Zemic Europe load cells will be supplied with a unique calibration certificate with the values determined during the production process.

Zemic Europe offers a wide range of load cells. The load cells are divided into the following categories:

• Single Point load cells
• Compression load cells
• S-Type load cells
• Shear Beam load cells
• Dual Shear Beam load cells
• Pancake(Low Profile) load cells
• Onboard load cells

In addition to this standard categories Zemic Europe can also provide special load cells for a unique solution.

A load cell is an electrical instrument which is used to convert a mechanical force into an electrical output signal. The terminology for load cells can be found in the OIML R60 regulation for load cells.

Zemic force sensors:

Product: Sensor Straingage Measuring
HS code: 90318080
Origin: China

Zemic mounting assembly:

Product: Accessories Measuring Instruments
HS code: 90319000
Origin: China

Zemic straingages:

Product: Straingage Resistor
HS code: 85339000
Origin: China