Features To Look For In Scale Indicators.

Understanding the features you need.

Weigh indicators are electronic devices that are used to measure the weight of an object. They are commonly found in industries such as agriculture, transportation, and manufacturing, where accurate measurements are critical. Weigh indicators come in a variety of shapes and sizes, and they can be equipped with a range of different features to suit different applications.

Understanding the features you need.

Display Size: One common feature of weigh indicators is a digital display. This allows the user to see the weight measurement in real-time, and it can be helpful for recording and tracking weight data. Some weigh indicators also have a built-in printer, which allows the user to print out a record of the measurement for future reference. A good weigh indicator will have a decent sized display that will give you good visibility to record the weight.

Peripheral Support: Another important feature of weigh indicators is the ability to connect to external devices. This can include devices such as load cells, which are used to measure the weight of an object, or other equipment such as computers or printers. By connecting to external devices, weigh indicators can be integrated into larger weighing systems, allowing for more complex and sophisticated measurements.

Advanced Features: Some weigh indicators also have advanced features such as automatic tare, which allows the user to quickly and easily subtract the weight of a container or other packaging from the overall measurement. This can be useful for accurately measuring the weight of the contents of a container without having to manually subtract the weight of the container itself.

Another advanced feature of weigh indicators is the ability to perform automatic calculations. This can include calculations such as determining the average weight of multiple measurements, or calculating the total weight of a batch of items. These features can help to simplify the weighing process and reduce the potential for errors.

Some features needed will be dependent on the environment that your scale and weigh indicator will be located. For example, your scale and indicator will be in a washdown environment. This means that your scale will need to be sprayed down, thus potentially causing water to get inside of the indicator. The feature available for those type of environments you will want are indicators with “washdown” protection. This is usually a stainless steel or a completely sealed indicator that can withstand the extreme conditions that it is in.

CLOSING WORDS

Overall, weigh indicators are versatile and useful tools that can be equipped with a range of different features to suit different applications. From digital displays and printer capabilities to automatic tare and calculation functions, weigh indicators can provide accurate and reliable weight measurements in a variety of settings.

At American Scale we strive to bring you informed and useful content on all things scale systems related, including products from the top scale manufacturers. Be sure to check out our truck scale articles about truck scale foundation or how much do truck scales cost. We even have a guide to warranties. To learn more about bench scales, it would be good to check out our other articles such as “Bench Scale Basics'' and “How Much Does A Bench Scale Cost?”. These articles will help with the basics of bench scale ownership. Also, take a look at our “Common Problems With Bench Scales'', to help prolong the lifespan on your scale.

Weight Indicator Issues.

Weigh Indicator Issues.

Understanding the environmental factors that can contribute to indicator issues.

Weigh Indicator Issues.

Mechanical and operational issues can and will occur during the life of scale ownership. Scale manufacturers have certain standards when it comes to scale care and scale calibration. When operating your legal for trade scale and indicator, there are factors that will add to potential issues but can be prevented with an understanding of which issues can arise. This will help you prolong the lifespan of your scale system and also help you avoid other common problems. You can ensure that your weighing system performs accurately by choosing components suited to your application and taking steps to control environmental and other forces acting on the system. This article discusses the factors that can affect your weighing indicator’s accuracy and provides advice and DIY fixes for potential issues. 

UNDERSTANDING THE FLOW OF COMMUNICATION

A weighing system and weighing application can take any of several forms but typically includes one or more load cells that support (or suspend) a weigh vessel or platform, a junction box, and a weight controller. Sometimes you will see certain setups with a remote display or scoreboard. When a load is applied to the weigh vessel or platform, a portion of the load is transmitted to each load cell. Each cell sends an electrical signal proportional to the load it senses via a cable to the junction box. The load cell signals are summed in the junction box and sent via one larger cable to a weight controller, which converts the summed signal to a weight reading. This weight reading's accuracy can be affected by the system components' quality and the system's installation and operation in your environment.

INTERFERENCE WITH INDICATOR

Weigh indicators communicate with the Load cells by receiving an electrical signal, which is processed by some type of weight controller that then outputs the weight onto the scale’s digital indicator. If it is an analog or electronic load cell there are factors that can add to inaccurate weight measurements. Interference occurs during any part of the process can lead to inaccurate weight readings between the load cell and scale indicators.

Below are just a few of the more common types of interference that we see when operating your scale and indicator. 

• Temperature – As temperatures increase wire resistance increases as well, causing voltage to drop, which can lead to the scale controller displaying results that are actually different from the load cell’s output.

• Moisture – From time to time, condensation or moisture can build up on the load sensor, which can affect electrical outputs and cause interference in the signals being sent from the load cell to the display indicator.

• RFI and EMI – These can create additional input signals, or noise that can also cause the scale controller to display an incorrect weight.

Temperature: A factor that some can overlook is the impact temperature has on your indicator. A load cell cable conduit that's subject to large temperature changes or that runs more than 50 feet from the junction box to the weight indicator can be affected by temperature fluctuations, which cause resistance changes in the cable. This can cause excitation changes, in turn causing load cell signal changes. To prevent these temperature problems, use six-wire load cell cable, which allows the weight controller to make ratiometric readings of the load cell signal that ignore excitation-change-induced changes. Essentially the extreme temperature changes can cause a chain reaction from the cable to junction box, thus sending an inaccurate signal to the indicator. 

 INTERFERENCE WITH SIGNAL TRANSMISSION

In addition to ensuring that the load cells measure only the desired weight, it's equally important to ensure that the weight controller measures only the load cell electrical signal. Radio frequency interference (RFI), electromechanical interference (EMI), moisture, and temperature can all interfere with this electrical signal.

RFI and EMI. Just as vibration is mechanical noise (that is, interference) to a load cell, RFI and EMI are electrical noise to the load cell signal sent from the cells to the weight controller. RFI and EMI sources include lightning, portable two-way radios, large power lines, static electricity, solenoids, and electromechanical relays. One major step toward preventing these electric noise sources from affecting your weighing accuracy is to isolate the load cell low-voltage signal (typically equal to 1 millionth of a penlight battery's output) in a shielded cable and then route the cable in a conduit separate from other cables. But be aware that the load cell cable shield can also be an open door for electrical noise. To prevent the noise from affecting your load cell function, properly ground the shield by tying it at only one end to a true ground, which will prevent the shield from forming a ground loop.

Moisture. Moisture that enters the weighing system's junction box can wick itself into the cables to each load cell and reduce the capacitance between signal lines. This causes the load cell excitation lines (the lines carrying electrical energy to the cells) to couple with the signal lines (the lines carrying the cells' signals back to the junction box), creating electrical noise that can affect the weighing accuracy. To avoid this, use a waterproof NEMA 4-rated junction box and plug any unused junction box holes. If moisture is present in your environment, also use load cells that are hermetically sealed at both the strain gauge area and the cable entry. The strain gauge area should be welded shut. The cable entry, which is the most vulnerable to moisture because moisture can wick up through the cable, should have a welded fitting that includes a glass-to-metal hermetic header.

At American Scale we strive to bring you informed and useful content on all things scale systems related, including products from the top scale manufacturers. Be sure to check out our truck scale articles about truck scale foundation or how much do truck scales cost. We even have a guide to warranties. To learn more about bench scales, it would be good to check out our other articles such as “Bench Scale Basics'' and “How Much Does A Bench Scale Cost?”. These articles will help with the basics of bench scale ownership. Also, take a look at our“Common Problems With Bench Scales'', to help prolong the lifespan on your scale.

Weigh Indicator Cost Guide.

Introduction

An industrial scale indicator is an important part of a scale and helps collect and read information. Pricing an indicator can seem a bit overwhelming, especially since it can be a bit of a chore to locate accurate prices for scales and accessories. Weight indicators are digital or analog display devices that indicate the weight of an object located on a connected scale. The weight and measurements standards are created and maintained by the National Conference on Weights and Measures (NCWM). The indicator is a very important part of owning a scale and a good indicator will make weight measurements a lot easier and efficient to obtain. 

Breaking down the cost

When breaking down the cost of scale indicators, you need to figure out what you are using the indicator with. Indicators will have varying features and options that will cater to the application that you are using your scale for. In the next sections ahead, we will break down the factors that contribute to the cost of your scale indicator. 

Indicator Types

Weight indicators are available with a wide variety of features designed for specialized applications. Depending on the application and the type of device needed will determine the primary functions needed. Weight indicators are programmed to work with different scale types to work with a scale system and vary in type by a digital or an analog readout. There are other features that can be included with an indicator like counting, checkweighing and wireless functionality. 

Modern weight indicators are generally used in industries such as industrial, factories, warehouses, shipping and receiving, food, chemical, energy and just about any other industry where materials are being weighed. 

One misconception to those new to industrial scales is that the indicator does everything. In reality, the weight indicators are not the ones that perform the weighing of an object. What happens is that the devices convert the weight measured by load cells into a digital readout. Essentially, weight indicators are like the computer for the scales. 

what does it cost?

When choosing an indicator that you think is the best option you will definitely look at the overall cost of everything included. Below are our pics along with prices on which weigh indicators will work well for your operation. 

Entry level

Ohaus T31P:

Designed with affordability in mind for basic industrial applications, the T31P combines high-impact ABS housing with a large high contrast backlit LCD display, bi-directional RS232 and 100-hour internal rechargeable battery. The T31P also features software for weighing and simple parts counting.

• Applications: Weighing, Parts Counting

• Display: Backlit liquid crystal display (LCD)

• Operation: AC adapter (included) or rechargeable battery (included)

• Communication: Easy access communication port including RS232 interface (included)

• Construction: ABS housing and painted steel mounting bracket, non-slip rubber feet

• Design Features: User-configurable resolution up to 20,000d/6,000e, OIML Approved, NTEP Certified and Measurement Canada Approved

Cost: Starting at $445

Mid Level

Rice Lake 480 Legend series:

Rice Lake is no stranger to the scale industry. Their industrial-strength Legend Series indicators are built for dirty, wet environments and demanding workplaces, inside or out.  Advanced circuitry withstands electrical noise, power disturbances and transient spikes that are common to industrial applications. The Legend Series offers a valuable solution for a variety of applications, from basic weighing to batching. Built-in gross/net modes provide quick flexibility for everyday needs. Also utilize the 480’s custom ticket printing to modify

• LCD backlit display

• Time and date, battery backed

• Local/remote operation

• Numeric keypad 

• Keyed entries for setpoint values 

• Programmable ticket formats for gross, net, accumulator and setpoints

• Adapter filter or rolling average filter

• Operator functions through menu for audit trail, preset tare, unit ID, accumulator, time and date, setpoints, communications and print formats

Cost: Starting at $750

High Level

Cardinal 825 Spectrum

The Cardinal 825 Spectrum indicator is a top of the line weigh indicator that is loaded with great options and features. The 825 is equipped with a back-lit LCD touchscreen display and stainless steel enclosure, coupled with 64 MB of memory. With connectivity options via 4 bi-directional RS232 serial ports, 110/100 Base-T Ethernet port, 2 USB A host ports, and 1 USB B device port, there is no end to this indicator’s potential. The programming options can link up to 8 operators to use. Other features include a time/date function, adjustable filtering, Gross, Tare, and Net conversion, QWERTY keypad and navigation keys. NTEP legal-for-trade and OIML certified. Supports up to 14 350-ohm load cells.

• 64 MB User Memory

• 640 x 480 Pixel Full-Color LCD

• Interactive Touchscreen Display

• Internet File Management

• IP66 Enclosure Rating

• Navigation Keys

• NTEP Legal for Trade

• OIML Certified

• Unlimited Truck Storage ID’s

Cost: Starting at $2,315

Washdown

Rinstrum x320 Washdown

The X320 combines innovation in industrial design and engineering excellence to create an instrument that is ideal for use in food processing, automotive, chemical or pharmaceutical applications or applications that require reliable operation in harsh environmental conditions. The X320 indicator builds on Rinstrum's already successful R320 indicator.

Constructed from a plastic alloy that is:

• Food grade

• Chemical resistant

• Temperature resistant

• Impact resistant

IP69K rating: the industry's highest environmental protection rating - designed to withstand cleaning with high pressure water jets (1400psi) at high temperatures (up to 80oC) from multiple angles.

Built-in check weigh function  with 3 coloured high intensity LEDs

Isolated outputs - Over, Under, Pass. High side driver up to 400mA, allowing direct connection to PLCs and external actuators to be driven directly

Cost: Starts at $715

Conclusion

The cost of a weigh indicator will vary depending on options, application and level of indicator. As stated and shown above, weigh indicators have a lot of differences that separate them from each other. The cost can be anywhere from $450 to over $3,000. Remember that the features and options that you select can impact the cost of your indicator. Evaluating your weigh operation and listing the things you will need and not need will make the selection process a lot more simpler.