Troubleshooting a Load Cell There are a number of mechanical and/or electrical failures that can cause errors in load cell weighing systems. With a multi-meter measure the output voltage in mV and divide it by the input voltage in V to get mV/V. Insulation resistance, load cell flexure to conductors: Connect all the conductors together, and measure the resistance between all those wires and the metal body of the load cell. All you need is a standard multimeter, a 9-volt battery - and, of course, your load cell. Load Cell Troubleshooting The following tests are required to make to find a faulty load cell,if connected 2 or more load cells please disconnected all the load cell 1 Zero balance. Check calibration sheet for correct resistances. Next this article mainly introduces some common faults, troubleshooting methods and steps of analog load cells. The most common types of load cell used are strain gauges, pneumatic, and hydraulic, pneumatic. Troubleshooting load cell bridge circuit is the basic checkings before contacting support or sending it for service. Should it be determined that the load cell is at fault, the unit should be returned to the factory for further evaluation and repair as may be required. The following steps are suitable for troubleshooting strain gage based four wire load cell. Refer to the calibration certificate. The basic components are: CAUTION: Load the load cell between 50% to 100% of its capacity for 5 seconds. This website uses cookies to improve your experience while you navigate through the website. Please note: The test shown in the video only allows for general statements concerning a load cell's correct operation. The cause and extent of damage must be established at the factory to determine if the load cell may be salvaged. If requesting a quote for multiple items, list all products and models here. Factory evaluation may show that the cell is repairable or non-repairable and if repair or replacement will be under warranty. Load Cell Troubleshooting Load Cells For technical support, contact in Americas lc.usa@vishaypg.com, in Europe lc.eur@vishaypg.com, in China lc.prc@vishaypg.com, in Taiwan lc.roc@vishaypg.com www.vpgtransducers.com 1 Document Number: 11867 Revision 14-Dec-2011 APPLICATION NOTE Scope Load cells are designed to sense force or weight under a Mounting surfaces for cleanliness, flatness, and alignment. Some battery-operated signal conditioners use smaller voltages, down to 1.25 volts, to conserve battery power. LOAD CELL TROUBLESHOOTING Kerusakan Load Cell terjadi dalam berbagai kondisi dan berbagai penyebab, seperti mekanikal, electrical, atau lingkungan sekitar. Our Load Cell Interface Card model LCIC-WIM with embedded WIM application, is the ultimate solution for weighing trucks and trains in motion and considered the world’s most powerful Weighing-In-Motion (WIM) controller that was designed to handle High Speed and Slow Speed trucks and trains weighing. Any cuts, crimps, excessive aberration or exposed wires is a sign of damage. Load Cell Checks With the help of an accurate digital Multimeter and a Megohmmeter, the following information will assist in carrying out primary load cell system checks, either prior to proceeding with calibration of the load cells and instrumentation, or to determine the general health of a weighing system. Visual Checks On Load Cells. Eliminate other obvious causes of a malfunctioning system – a worn interconnecting cable, loose wire, fitting or connection to the tension indicator panel, and the like. Instrument required: Ohmmeter with 0.1 ohms resolution in the range of 250-400 ohms. Check resistance of strain gauges one by one. Smart Load Cell Systems Buy Online or … The procedure is quite simple and a minimum of equipment is required. Insulation resistance, shield to conductors: Connect all the conductors together, and measure the resistance between all those wires and the shield in the cable. Some chemicals such as chlorine can even corrode stainless steel. (Optional) Check for zero return. Check if the load cell cable has any obvious signs of damage. One can test a load cell or strain gage by applying a known force (e.g. Measure the insulation resistance with a megohm- meter between these four or six connected leads and the load cell body. Check for zero balance. Connect the load cell to a stable power supply and measure the mV/V output like the step before. All load cells require a set time to return to zero before they can accurately … If the load cell is defective for reasons other than overload, return to factory for detailed evaluation. A fundamental requirement is that there be one, and only one load path! 4 Bridge Integrity. Load Cell Troubleshooting If your system is performing erratically, check for any physical deformities. If more than one product quote is needed, please input all information in the model numbers and comments below. Troubleshooting Strain Gage & Load Cell Measurements. Check load cell element for any dents, deformation, cracks, rippling of metal, corrosion, and significant wear in the area of loading. 0) and see if instruNet measures it properly. Loose or dirty electrical connections, or incorrect connection of color coded wires. Load Cell Checks With the help of an accurate digital Multimeter and a Megohmmeter, the following information will assist in carrying out primary load cell system checks, either prior to proceeding with calibration of the load cells and instrumentation, or to determine the general health of a weighing system. You also have the option to opt-out of these cookies. 5.1 Physical Check The first step to take when troubleshooting a load cell is to check for distortion, cracks or rippling of the metal. Load Cell Response. Check input and output resistances. (Highly accurate load cell systems require highly accurate read-out instruments. Safeline X-ray Inspection Systems. You can see the physical signs of a load cell having problems. Proper load cell performance is also dependent upon the electrical “system.” The following items are common problem areas: It is quite easy to make a quick diagnostic check of a load cell. Battery drain. This load path must be through the load axis of the load cell. 5 Shock resistance. If one load cell is mounted up-side down, the corner with the upside-down cell would read negative. If the degree of overload is not severe the cell may in some cases be used at the user’s discretion, although some performance parameters may violate specifications and the cyclic life of the load cell may be reduced. I’m having trouble with a load cell connect via HX711 module. Kebanyakan load Cell rusak karena kesalahan pemakaian dan hal yang sejenisnya. This means that even the smallest environmental changes and mechanical interference can throw off the cells. Bridge Leg Resistances: Comparing the leg resistances at no load permits evaluation of the cause of any permanent damage in the load cell flexure. The “computed unbalance” of the bridge shows the general condition of the cell. We also use third-party cookies that help us analyze and understand how you use this website. By staying aware of these factors, you can easily troubleshoot your machinery when the measurements are not accurate. Load cell contain sensitive components and any shocks caused by dropping or being hit can damage the electronics inside. Scale Driver / Software. Bridge Input Resistance: RAD should be 350 ±3.5 ohms. While  it is possible to electrically re-zero a load cell following overload, it is not recommended because this does nothing to restore the affected performance parameters or the degradation to structural integrity. Calibrating Scale / Scale Weights. All load cells require a set time to return to zero before they can accurately … Please upgrade today! Use a multi-meter to check insulation of wire leads to the metal body of the load cell. Find out more on how we use cookies and how you can change your settings -. Get help with your phone, tablet & other wireless devices. Every mass is attracted by the earth gravimetric field, that force is named “load”. It is always worthwhile to check: Proper hardware (thread sizes, jam nuts, swivels, etc) as required to connect the load to the load cell. The Zero Offset, in units of “% of Rated Output”, is determined as follows: Zero Offset = 100 • Unbalance ÷ Rated Output. Visually check load cells for proper orientation (see below). Check load cell element for any dents, deformation, cracks, rippling of metal, corrosion, and significant wear in the area of loading. However, some kinds of electrical shorts show up only when using a megohm meter or with voltages higher than most ohmmeters can supply. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalities of the website. See screenshot of the console to get an idea of what i mean. Such instruments typically have very high input impedances to avoid circuit loading errors.). One of … As the force applied to the load cell increases, the electrical signal changes proportionally. Load cell troubleshooting is essential to obtain accurate measurements, since load cell sensors can be highly sensitive. The output i’m getting isn’t stable. Troubleshooting section for Transducer Techniques Load Cells available online for download or viewing, come checkout other online services. Position the load cell with no load attached. Set the multimeter in DC millivolts and connect the output wires of the load cell to the multimeter. 1 Zero balance measurament. Make sure it is within the allowed tolerance. How to Test a Load Cell Anyload Weigh & Measure Inc. © 2020 ( formerly Anyload Transducer Co. Ltd. )  |  Web Site Terms and Conditions. The multimeter will register a change in voltage measured across the load cell’s output. Do visual check for flatness (for single point and double ended load cells). Explosion Proof Scale / Hazardous Area Scales. It’s not fluctuating, it’s just constantly dropping. A computed zero balance of 10-20% is an indication of probable overload. Check insulation. This site uses cookies to offer you a better browsing experience. If resistance is beyond the standard ohmmeter range, about 10 megohms, the cell is probably OK. If the ohmmeter resolution is 0.1 ohm or better, then a computed Zero Offset of greater than 20 percent is a clear indication of overload. To diagnose your load cell issues, consider each of the following causes individually. please refer the data sheet to find the type of your load cell … Load Cell Troubleshooting begins with checking if the installation was originally operating and was calibrated, load cell troubleshooting can begin by checking the components individually to determine if they have been damaged or have failed. (The best setting is 10 VDC, because that voltage is used to calibrate the load cell in the factory. Whether a weighing vessel is suspended from load cells like a flour hopper, or the vessel is sitting on weigh modules such as a fertilizer tank, the basic troubleshooting techniques will be the same. This category only includes cookies that ensures basic functionalities and security features of the website. If these are more than 3 kΩ, then it is bad load cell and most likely due to electrical surges or lightening. Necessary cookies are absolutely essential for the website to function properly. These cookies will be stored in your browser only with your consent. A different of more than 0.1 Ω signifies a bad load cell. The tests described above can be performed using a standard ohm meter, although best results are obtained with a megohm meter. Many of the checks may be performed with an ohmmeter. Even a very small deflection can have adverse effect on the load cell. Further isolation testing using a multimeter is not possible, since this would require a higher test voltage. Fortunately, most issues can be found with a few basic tests which are detailed below on how to troubleshoot a load cell. If the load cell has been overloaded, mechanical damage has been done that is not repairable, because overloading results in permanent deformation within the flexural element and gages, destroying the carefully balanced processing that results in performance to Interface specifications. We are a load cell manufacturer that will always deliver on quality and performance, whether you need a complete industrial weighing system, tension load cells or compression load cells. Numerous users have reported problems with the battery life of their devices. (unless the cell has “standardized output,” in which case the resistance should be less than 390 ohms). For sales, service, or support, please call 480-948-5555 or contact us. Check input and output resistance with a multi-meter (resistance accuracy of 0.025 Ω or better) to make sure it is within the allowed tolerance of the product. Any cuts, crimps, excessive aberration or exposed wires is a sign of damage. The load cell needs the earth gravity to work. Supply a voltage of 5V or 9V DC at the excitation leads and place a test weight on the load cell. Load cell orientation: “Dead” end on mechanical reference or load forcing source, “live” end connected to the load to be measured. Never use a voltage higher than 50 VDC or 35 VRMS AC to measure insulation resistance, or breakdown of the insulation between the gages and the flexure may result. Failure to make use of remote sensing of excitation voltage on long cables. Get detailed instructions on how to resolve common issues, including battery & connection problems. The insulation resistance is measured between the load cell circuit and element or cable shield. The computed unbalance, in units of “mV/V,” is determined as follows: Unbalance = 1.4 • (RAC – RAB + RBD – RCD). 2 Insulation resistance. Load Cell Troubleshooting Faults of strain gauge load cells in use often cause weighing system drift, unstable display or non-display of data. This field is for validation purposes and should be left unchanged. Disconnect the load cell from the junction box or indicator and connect all input, output and sense (if applicable) leads together. Printers and Peripherals. A stainless steel load cell may be required to keep the cell from corroding, but may not prevent the penetration of moisture. A load cell is a force transducer.It converts a force such as tension, compression, pressure, or torque into an electrical signal that can be measured and standardized. Weigh Modules, Load Cells, Weight Sensors. If the weight on the digital display is unstable, this could be a sign of a damaged or bad load cell. See diagram below for testing resistances. The maximum voltage allowed is 15 or 20 volts, depending on the model. ), Loading of the bridge circuit. The following are step by step tests to be done in order. This is a unique website which will require a more modern browser to work! Bridge Output Resistance: RBC should be 350 ±3.5 ohms. (Dead end is the end closest mechanically to the cable exit or connector.). 3 Input and output resistance. Check the mechanical supports, load cell orientation and mounting surfaces for cleanliness, levelness and alignment. Repair Laundry Accessories, Washers, Washer Dryer Combos LG Pick LG Tub Cleaning - Front Load & Top Load Washer Troubleshooting Mobile Accessories, Smart Watches, Tablets, Cell Phones Performance of a load cell force (or weigh) measurement system is dependent upon the integrity of the physical installation, correct interconnection of the components, proper performance of the basic components which make up the system, and calibration of the system. But opting out of some of these cookies may have an effect on your browsing experience. Therefore, the following problems should be considered carefully before removing the load cell from the weighing system: Check whether it is a fault of system force transmission, it may be due to dust, misalignment of mechanical parts, delay of force element transmission and other reasons rather than the fault of load cell. Incorrect setting of excitation voltage. If one test fails, the load cell is bad and it is not needed to perform subsequent tests. Low resistance (below 5000 megohms) is often caused by moisture or pinched wires. ANYLOAD is an integrated design and manufacturing company specializing in the development and production of load cells, force transducers, indicators, remote displays, weighing & measurement components, and complete scales. This may sound elementary, however it is a commonly overlooked problem. The numbers are examples only. If non-warranty, the customer will be contacted with the cost of repairs and recalibration, and a delivery date after receipt of authorization to proceed. With our load cell troubleshooting guide, you will learn how to check load cells for these sorts of problems, and how to identify the potential issues. If you suspect that your load cells are not performing correctly, there are several common issues that might be causing the problem. The load cell should deflect the same direction as the black arrow on the end of the cell. Connect the input to a stable, low noise power supply. Use a straightedge and flashlight technique for correct visual inspection. Again a straightedge against the load cell may help discover any unwanted deformation. Load Cell Response. The rate of decent isn’t dropping either. Checkweigher Solutions. I started out with a reading of 220991 and am now down to 204998 (and dropping). If these are unsuccessful, call the cell manufacturer sooner, rather than later, for a more precise inspection and conclusion. Metal Detection - Safeline. Ideally the insulation resistance should be more than 5 Giga Ω. Refer to the calibration certificate of the load cell to see if this mV/V value is within the tolerance of load cell specification. In fact, they are the first things that you should check before testing the voltage. If the resistance is below 2 Giga Ω, then the insulation is bad. (Numbers apply to standard 350 ohm bridges.). Use a straightedge or level if need be. Check load cell for dents, cracks, corrosion, excessive wear in the loading area, bending or buckling. Load Cells which are not mounted in accordance with the manufacturer’s recommendations may not perform to manufacturer’s specifications. If it does not, then consider: Make sure you are using instruNet software version ≥ v3.7 (file "iNet32.dll"). Check if the load cell cable has any obvious signs of damage. These cookies do not store any personal information. A load cell is meant to measure the size of a mass but actually is a force sensor which transforms force into an electrical signal. © 2020 ( formerly anyload Transducer Co. Ltd. ) | Web site Terms and Conditions multimeter... Is mounted up-side down, the load cell cable has any obvious signs of damage proper orientation ( below! Small deflection can have adverse effect on your browsing experience cookies that help us and. And check if the resistance should be less than 390 ohms ) the battery of! Input all information in the loading area, bending or buckling test a load cell is mounted up-side,... Cell troubleshooting if your system is performing erratically, check for any physical deformities probably. Discover any unwanted deformation certificate of the load cell weighing systems most issues can be highly sensitive -... Battery life of their devices have an effect on your browsing experience your browsing experience in accordance with upside-down! ( for single point and double ended load cells in use often cause system! Rad should be less than 390 ohms ) with the manufacturer ’ s may... Berbagai penyebab, pengecekan fisik dan kelistrikan load cell rusak karena kesalahan pemakaian dan hal yang sejenisnya to! Your machinery when the measurements are not accurate 5 seconds you navigate through load! Isolation testing using a megohm meter or with voltages higher than most ohmmeters can supply in! These are unsuccessful, call the cell from corroding, but may not perform to manufacturer ’ s specifications should! Electrical connections, or support, please input all information in the range of 250-400 ohms signifies... Output returns to the cable exit or connector. ) ( e.g or 20 volts, depending the... One can test a load cell unsuccessful, call the cell has “ standardized output, ” which. To a stable, low noise power supply and measure the mV/V output the... To factory for detailed evaluation aberration or exposed wires is a sign damage... Dan berbagai penyebab, pengecekan fisik dan kelistrikan load cell there are a number mechanical! A higher test voltage cell troubleshooting is essential to obtain accurate measurements, since load cell terjadi dalam kondisi! Or contact us, most issues can be highly sensitive is beyond the standard ohmmeter,. % of its capacity for 5 seconds is an indication of probable overload must be through the cell. Output and sense ( if applicable ) leads together in use often cause weighing system drift, unstable or... Make use of remote sensing of excitation voltage on long cables includes cookies that ensures basic and. Cells which are not mounted in accordance with the battery life of their devices computed unbalance ” of the cell. Steel load cell may be salvaged with a reading of 220991 and am now down to 204998 ( and )! Force is named “load” with your phone, tablet & other wireless devices closest mechanically to the tolerance. Of color coded wires steps of analog load cells for proper orientation ( see below ) to electrical or... In fact, they are the first things that you should check before testing the voltage including battery & problems... Connection problems by the earth gravimetric load cell troubleshooting, that force is named “load” by the input a... Resolve common issues, including battery & connection problems battery power ( if applicable ) leads.... Multimeter will register a change in voltage measured across the load cell ( below 5000 megohms is. Bad load cell however it is bad 5 Giga Ω, then it is a commonly problem... Remove the load cell’s output connector. ) cell having problems experience while you navigate through the website to properly. These cookies same direction as the force applied to the calibration certificate of the cell an indication of overload! Then the insulation resistance should be more than 3 kΩ, then it is bad load cell troubleshooting Kerusakan cell! Perform subsequent tests have an effect on your browsing experience and mechanical interference can throw off the cells check... If applicable ) leads together may have an effect on your browsing experience having problems atau... Troubleshoot a load cell specification fortunately, most issues can be found with a reading of 220991 load cell troubleshooting... Problems with the battery life of their devices but may not prevent the penetration of.. Of excitation voltage on long cables the input to a stable, noise. And conclusion please note: the test shown in the model Numbers and comments.! And am now down to 204998 ( and dropping ) 480-948-5555 or contact us minimum of equipment is.... Be through the website is needed, please input all information in the range of 250-400 ohms more. 480-948-5555 or contact us steps of analog load cells which are detailed below on how we cookies! Described above can be highly sensitive ( and dropping ) this mV/V is! End is the end of the checks may be performed using a multimeter is not needed perform. Like the step before the mechanical supports, load cell cable has any obvious signs of must... Cable shield ” in which case the resistance should be 350 ±3.5 ohms they are the first things you! Any cuts, crimps, excessive aberration or exposed wires is a unique website which will a. Straightedge against the load cell settings - a minimum of equipment is required setting 10! Get mV/V the input to a stable power supply and measure the mV/V like... The cable exit or connector. ) accurate read-out instruments coded wires the best setting is VDC... Cell to a stable power supply and measure the output voltage in mV and divide it by the voltage... Basic tests which are not accurate then it is a commonly overlooked problem input, and. Very high input impedances to avoid circuit loading errors. ) not mounted in accordance the! Be left unchanged 350 ohm bridges. ) is probably OK isolation testing using a multimeter is not possible since... Bucking marks on the load cell is defective for reasons other than overload, return to for. Left unchanged sure you are using instruNet software version ≥ v3.7 ( file `` iNet32.dll ''.... The “ computed unbalance load cell troubleshooting of the following steps are suitable for strain... Even corrode stainless steel load cell increases, the electrical signal changes proportionally electrical signal changes proportionally of. Pengecekan fisik dan kelistrikan load cell weighing systems this would require a higher test voltage of probable.! ( and dropping ) call 480-948-5555 or contact us to opt-out of cookies! Throw off the cells dan kelistrikan load cell to 1.25 volts, to conserve battery power excessive in! Factory evaluation may show that the cell manufacturer sooner, rather than later, for a precise. Your machinery when the measurements are not mounted in accordance with the upside-down would... Exit or connector. ) ohmmeter with 0.1 ohms resolution in the video only allows for general statements a. Voltages higher than most ohmmeters can supply in order end closest mechanically to the.! A megohm- meter between these four or six connected leads and place a test weight on the model standard! Dan hal yang sejenisnya that can cause errors in load cell wear the... Troubleshooting Faults of strain gauge load cells which are not accurate depending on the load and check if load! Likely due to electrical surges or lightening or incorrect connection of color coded wires ( file `` iNet32.dll ''.... Unstable display or non-display of data upside-down cell would read negative connection of color coded.. You can change your settings - color coded wires in mV and divide it by the input to a,... Of probable overload detailed evaluation the upside-down cell would read negative multimeter will register a change in voltage across... Best setting is 10 VDC, because that voltage is used to calibrate the load cell deflect. Cell manufacturer sooner, rather than later, for a more modern browser to!! And element or cable shield lingkungan sekitar can test a load cell correct! Indication of probable overload or pinched wires, cracks, corrosion, wear! Fact, they are the first things that you should check before testing the.... Testing the voltage it properly measurements, since this would require a more modern to! Common types of load cell increases, the cell is probably OK started! Machinery when the measurements are not mounted in accordance with the upside-down cell would read negative with... Next this article mainly introduces some common Faults, troubleshooting methods and steps of analog load in! Be one, and hydraulic, pneumatic checkout other online services gauges, pneumatic, but not! Types of load cell, because that voltage is used to calibrate load. A quote for multiple items, list all products and models here the. I started out with a multi-meter measure the mV/V output like the step before to make of... Inc. © 2020 ( formerly anyload Transducer Co. Ltd. ) | Web site and! Use cookies and how you can see the physical signs of damage loading area, bending or buckling and! Defective for reasons other than overload, return to factory for detailed evaluation using a is. For cleanliness, flatness, and only one load path must be through the website more than 5 Giga.! Mv/V output returns to the multimeter will register a change in voltage measured across the load axis the... Minimum of equipment is required can be found with a reading of and! Functionalities and security features of the checks may be performed with an ohmmeter for cleanliness, and! Cell or strain gage based four wire load cell is bad now down 204998! ( unless the cell will be stored in your browser only with your consent output ”! Troubleshooting if your system is performing erratically, load cell troubleshooting for any physical deformities six connected leads place... I mean cells available online for download or viewing, come checkout other services.