Ohaus Scout STX – a touchscreen scale done right

The first scale with a touchscreen display that I ever used took a while to start up, reacted sluggishly and – if I remember this correctly – required me to set up a user account before it would let me actually use it. That was a few years ago, but still, I was a bit skeptical when Ohaus announced that the newest model in their legendary Scout series would now have a touchscreen, too. However, after purchasing the cheapest Scout STX (the STX 421) and testing it extensively over several weeks, I can say that my worries were unfounded.

Startup time

As you can see in this short video, the Scout STX is even faster than the Ohaus Ranger 3000:


How many scales can truly claim to be so easy to set up that you never have to look at the manual? As an example, here’s how you change the language: Touch “Menu”, then you’ll see 8 settings, of which “Balance Setup” looks the most promising. You’ll now see another seven settings with “Language” being the first one:

Should you ever find yourself somewhere you didn’t want to go, you can simply touch “Back” to go back to the previous screen.

Somewhat embarrassingly, the only thing I actually had to look up was how to change into another application mode: Instead of going through the menu, you simply touch the application name shown in the top left corner of the screen. I’m just not used to things being so intuitive.

9 applications

The touchscreen really shines when it comes to different applications. As you can see in this video of me using the parts counting mode with auto-optimization, the STX can even replace a dedicated counting scale:

12 seconds into the video, the scale displays an entire number block to let me enter the average piece weight or number of samples. There’s simply no way to achieve this kind of application flexibility and user friendliness without a touchscreen.

Touchscreen disadvantages

One common complaint about touchscreens is the lack of tactile feedback. Fortunately, the most frequently used buttons on any scale, ON/OFF/Zero and Tare, were still kept as physical buttons on the Ohaus Scout STX.

You also have to consider that the fairly large screen needs a lot of power. The Scout STX can be used with four AA batteries, but those won’t last more than a few hours (6 according to Ohaus). It’s certainly a good idea to use the included power adapter whenever possible.

Links and further information

Using your smartphone as a scale?

So far, apps which claim to transform a smartphone into a weighing scale generally fall into one of two categories:

  • Simulators: They pretend to be a scale, but simply show a previously entered weight. Might be good for dealers wanting to rip off gullible customers, but certainly not much else.
  • Creative sensor use: Some apps try to make use of existing sensors in order to calculate the weight of an object. This could mean balancing your phone on a bag filled with air and placing an object on it while the app measures the inclination. Another app requires putting your smartphone on top of the object you want to weigh and then dropping both on a cushion. Of course, you’d also have to repeat the procedure with reference weight. Obviously, this is not exactly user friendly. While I haven’t tried any of the apps myself, they mostly received one star reviews. Unlike the simulators, which at least do what they pretend to be doing, it doesn’t look like these apps work well enough to be even remotely useful.

Therefore, I was surprised when I saw the following video featuring Peach-O-Meter, an application which compares the weight of two peaches:

It’s easy to use and seem to be working better than anything available so far. This became possible thanks to 3D Touch, a feature on the new iPhone 6s. A new layer of capacitative sensors registers how hard you press on the pliable glass:

Pressing down onto the glass bends the glass very slightly at the point of contact, shortening the distance between your finger and the corresponding capacitor plate in the array beneath the display.

Putting peaches on your screen is probably not what Apple had in mind when they introduced 3D Touch as “a new way of interacting”. Originally, the program author had planned to use grapes, but discovered that the iPhone ignored them. He’s announced that he’s purchased calibrations weights and is planning to run further tests. There’s also at least one company which is trying to develop a professional app (with “calibration cubes”).

I’m looking forward to seeing where this leads, thought I’m skeptical concerning the usefulness of such an app. Want to weigh lightweight “objects” while you’re on the move? I’m sure you’d get much better results from an inexpensive pocket scale. Using your top-of-the line device in the kitchen has its own perils and reminds me of this sketch from a German comedy show:



Free software for scales and balances with RS-232 and USB

Are you still manually entering weight readings from your scale or balance on your PC? Is your scale equipped with a RS-232 or USB (virtual COM port) interface? If yes, you can eliminate manual data entry by connecting your scale to your computer and using our free software 232key.

232key automatically types the weight into any application

Our software runs in the background, listens to the COM port (serial port) your scale is connected to and waits for measurement values sent by the scale. Those values are then filtered, formatted and typed into the application running in the foreground at the current cursor position as simulated keystrokes. This means that 232key can be used to transfer the weight (or other measurement values) into any application that accepts keyboard inputs, e.g. Microsoft Excel, OpenOffice / LibreOffice Calc, Google Docs, a form on a website, etc.

In the following example, I used A&D’s FG-60KBM scale with an optional RS-232 interface (FG-OP-23). I connected it to my laptop with A&D’s serial cable (AX-PC09-SCA) and an inexpensive converter to USB (as my laptop doesn’t have a serial port). Upon pressing the “PRINT” key on the scale, the weight was typed directly into an input field on a website:
Transferring the weight from a scale to a website

Compatibility with scales and balances

To use 232key, you’ll need a scale with a RS-232 interface (aka. serial port, COM port, EIA-232) or an interface which appears as a (virtual) COM port when the scale is connected to your PC. This is the case for many (but not all) scales with a USB interface and for scales which support the Bluetooth Serial Port Profile.

Your scale or balance also has to send the weight in ASCII format. The weight has to be the first numeric value sent* and it should only be sent once (after you’ve pressed a key on the scale), not continuously.

The vast majority of scales and balances available on the market today fulfills these requirements. Just to give you a few examples, you should be able to use 232key with most or all scales and balances made by A&D (RS-232 only), Adam Equipment (RS-232 and USB), Ohaus** (RS-232 and USB), Kern**, MyWeigh (RS-232 only) and other well-known brands. New device profiles are constantly added!

Finally, an easy way to transfer data from your scale to your PC

We designed 232key to make your life easier. No complicated configuration is required. If your scale manufacturer or model is included in the list of predefined devices, you don’t even have to manually enter the interface parameters: Simply select your scale and click on “Default” to load the settings.
Interface settings

Not sure which COM port you scale is connected to? Press the “Auto” button and 232key will try to detect the port automatically (works with all devices which have some sort of hardware handshaking functionality, e.g. scales and balances made by A&D and MyWeigh’s popular HD series).

Do you know which decimal separator (point or comma) your scale is using? Why should you! 232key understands both input formats and lets you choose which output format you want.
Decimal separator

Would you like 232key to press an additional key after typing the weight, e.g. the “Enter” key to jump to the next row in a spreadsheet? No problem, simply specify the desired key in the “Format” tab.
Additional key

All of these useful and user-friendly features are available for free! Additional functionality is available in the paid “Plus” version of 232key.

Download and documentation

Please visit our product website 232key for further information and to download our free software. Should you have any questions or suggestions, please don’t hesitate to post them in our support section or as a comment below.

* We’ve added an exception to this rule for scales and balances made by Adam Equipment.
** Affiliate links.

Easily weigh aquatic animals using submersible scales

Regularly recording an animal’s weight is essential for keeping track of its health. However, weighing can be a traumatic experience particularly for aquatic and semi-aquatic animals as they have to be removed from the water where they spend all or most of their life.

Fortunately, several weighing instrument manufacturers have addressed this issue with new submersible scales. One such scale is the Ohaus Valor 2000W, shown below being partially submerged to facilitate the weighing of one of our company’s turtles:

Weighing a turtle on a semi-submerged scale

Turtle “Alpha” basking on top of the scale.

Thanks to it’s unique “flow-thru design which channels fluids that may enter the housing through strategically located drain holes”, this scale immediately sinks to the bottom of the aquarium while remaining fully operational. All that’s left to do is to wait until the animal takes a rest on the weighing pan and record the weight. There’s no better way to weigh aquatic reptiles, fish and marine mammals!

Available in capacities from 1.5kg to 15kg, Ohaus’ Valor 2000 can be found here.

How accurate are smart scales?

Are smart scales accurate weighing instruments or just simple bathroom scales with expensive connectivity features? To find out, I tested the Withings WS-30, Fitbit Aria and A&D UC-324NFC using class M1 weights.


Each of the scales had not been used before and was configured as instructed by the manufacturer. This included signing up for an account with Withings and Fitbit. In the case of A&D’s UC-324NFC, I took advantage of a function available in the Wellness Connected  app which let me “calibrate” the scale by entering the local gravitational acceleration.

The scales were tested under similar conditions with a stable temperature of around 22°C and were placed on a flat, hard surface. The Withings and Fitbit scales were left alone for a night after the initial configuration as I wasn’t quite sure how they determine the zero value: unlike older electronic scales, you don’t have to switch them on and wait for them to show ‘zero’, instead, you step right on (the UC-324NFC determines the zero point after you step off).

Test procedure

I used 20kg weights to test the scales at 40, 60, 80, 100 and 120 kg. This procedure was repeated 3 times for each scale (I did a lot of weight lifting that day).


The first column gives you the nominal weight (in kg) and the next three are the values as shown by the scales.

Withings WS-30

40 40.2 40.2 40.2
60 60.3 60.3 60.3
80 80.4 80.3 80.3
100 100.3 100.4 100.4
120 120.4 120.4 120.4

Fitbit Aria

40 40.2 40.2 40.1
60 60.2 60.2 60.2
80 80.2 80.2 80.2
100 100.3 100.3 100.3
120 120.3 120.3 120.4


40 39.95 39.95 39.95
60 60.00 59.95 60.00
80 80.00 80.00 79.95
100 100.00 100.00 100.00
120 120.00 120.00 120.00

As you can see, A&D’s UC-324NFC was the most accurate scale, never deviating by more than 50g from the true value. Its 50g resolution and gravity compensation function certainly paid off.

However, the Fibit and Withings scales did a great job, too. Looking at the measurement results in each row, you’ll see that they are either identical or off by just one scale interval (100g). We can therefore say that these scales were slightly less accurate, but still very precise* (or that their repeatability was still excellent). As far as your body weight is concerned, you’ll generally be less interested in absolute values and more in tracking changes (“am I loosing or gaining weight”) and these scales would be perfectly suitable for this purpose. Nevertheless, I was a bit surprised that Fitbit and Withings didn’t use the location I had entered during account creation to adjust the scale for the local gravity acceleration. This would most likely have improved their accuracy.

Overall, the results are very good. As far as I can tell from this test, you’re not just paying for the “smart” features, you get accurate scales, too.

Further information / where to buy:


  • Some links above are affiliate links.
  • My company used to sell A&D’s UC-324NFC in our German scales shop, but we don’t anymore. The Withings WS-30 and Fitbit Aria were purchased at retail prices, A&D’s UC-324NFC was purchased with a dealer discount.

*Meaning of accuracy and precision (as used in this article):
Accuracy and precision explained

RS-232 troubleshooting: fake chips

RS-232 is still the most popular interface for balances and scales. It is often described as “simple”, however, when things don’t work as expected, finding the cause can be difficult.

This article does not aim to be a comprehensive RS-232 troubleshooting guide (for this purpose, please refer to this PDF document from Agilent Technologies or the troubleshooting section on our 232key website). Instead, it is supposed to raise awareness of an issue that is often ignored: counterfeit ICs.

When you’ve tried everything and still can’t reliably communicate with your scale via RS-232, there’s a chance a fake chip may be the cause.

Just a few weeks ago, the thought of encountering counterfeit ICs in digital scales had not crossed my mind. Thanks to FTDI’s recent attempt to “brick” counterfeits via Windows Update, fake chips are now a hot topic on the web. While I don’t agree with the way FTDI tried to punish the end user, I wish the controversy had occurred a few weeks earlier. This would have saved me a lot of time.

Back then I was doing the final QC for several scales which were about to be shipped to a customer. The last item on my checklist was “bidirectional communication using RS-232”, something I had done many times before with this exact model. What should have taken a few minutes ended up taking me several days and nearly drove me crazy because the problems I encountered were difficult to replicate. Eventually, I arrived at the conclusion that something was very wrong with the MAX232CPE+ chips, which are responsible for converting TTL signals to RS-232 levels. After doing some research on the internet*, I started to suspect those chips were counterfeit. It seemed like a far-fetched idea** at the time, but I still desoldered them, took a few pictures and sent them to Maxim Integrated.

Fake MAX232CPE+ and MAX232EPE+

Counterfeit MAX232CPE+

Fake, fake and fake.

Thankfully, I received a reply in less than two hours:

“Yes these parts are counterfeit, they do not match markings of lots we manufactured.”

Now extremely suspicious of all MAX232s***, I disassembled a few more scales from 4 different suppliers. 3 contained ICs belonging to the MAX232 family, so I sent the pictures to Maxim Integrated, too. In addition to the chips used by the scale manufacturer which had prompted me to start this investigation, one chip used by another manufacturer was also flagged as counterfeit.

Counterfeit MAX232EPE+

Counterfeit MAX232EPE+

To be fair, my sample size is too small to draw meaningful conclusions regarding the entire weighing industry. However, if you’re in the business of making weighing instruments and were blissfully unaware of this issue, I hope this article serves as a wake-up call.

* I found documents like this one (16 MB PDF presentation by SMT Corporation) or this one (100 KB PDF, University of Conneticut), this article by Maxim Integrated and even videos of YouTubers walking through huge electronic component malls in Shenzhen where almost everything is counterfeit.

** Though not quite as far-fetched as the manufacturer’s idea that “static build up from the polystyrene packaging in road transportation” was to blame.

*** And also seriously angry at having wasted so much time doing something the manufacturer should have done. I won’t do any naming and shaming here, though.

Solution: Err 8.2 on Ohaus Defender scales

If your new Ohaus Defender shows “Err 8.2”, you have probably not yet removed the shipping spacers. These protect your scale from damage during transport, but have to be taken out before use.

1. Remove the stainless stainless steel platform pan. You’ll see 4 red plastic shipping spacers wedged between the overload protection screws and the upper frame of the platform:
Ohaus Defender 3000 shipping spacer

2. Remove these spacers by hand or with an adequate tool (without turning the overload protection screws):
Ohaus Defender shipping spacers removal

3. Place the stainless steel pan on the platform. Your scale is ready to weigh.

Solution: JShip key not working

You should feel and hear a distinct “click” when pressing the keys of your JShip parcel scale.
JShip-130 indicator

If that’s not the case or if you have to use excessive force, please do not try to use a sharp object as this might puncture the overlay. Instead, return your scale for repair or try repairing it yourself as described below.

We found that – in most cases – the buttons themselves are working fine and all you have to do is tighten the screws holding the PCB inside the indicator.

Please note that these are not official instructions and we do not accept any responsibility if things go wrong.

1. Open indicator housing

Remove all six screws on the back of the indicator. Note how they’re tightened very lightly. Remove plastic cover.
Open JShip-130 indicator

2. Tighten screws on PCB

There are 5 screws holding the PCB in place. Use a PH1 or PH2 screwdriver to tighten them as much as possible without over-tightening. If all screws are already firmly tightened, try carefully turning just the two screws marked below clockwise by no more than 1/8 of a turn.
Inside JShip-130 indicator

Press the keys to see if the problem has been resolved.

3. Close indicator housing

Put the plastic cover back in place and very lightly tighten the six screws. If you turn them too far, the rather brittle cover might break.

World’s smallest wheel load truck scale

Today, I finally received my sample of the world’s smallest wheel load scale! I’m happy to share my first impressions with you.

Made by Siyue Yiri Electric Weighting Machinery Apparatus Manufacturing Co., Ltd. from Wanxiao in China, this scale has an impressive capacity of 12t and fits easily in the palm of your hand:
World's smallest wheel load scale

Driving a vehicle onto the small raised platform can be a bit tricky. If you’re not careful, you could easily obscure or even scratch the display. The photo below shows how the tire should be positioned:
Wheel load scale

While smartphones are becoming so big that soon we’ll all be carrying a purse, this scale is a remarkable example of the miniaturization of weighing technology.

New Scales and Balances coming in 2014


A&D has confirmed that the SJ-WP series of compact bench scales is going on sale in Europe in the first quarter of 2014.

A&D SJ-30KWP Food Scale

To understand what’s so ingenious about this scale, you should know that until now, compact scales were either fast or they had a high degree of ingress protection. It was not possible to have both a very short stabilization time (<1s) and resistance to dust and liquids in a compact instrument. The reason for this is that the air pressure inside the housing of the scale changes when a load is applied (or removed). For accurate measurements, the air pressure inside and outside has to be equalized. Of course, this could be achieved by simply building a few holes into the housing, but then you would allow dust and liquids to enter. The conventional solution has been to use selectively permeable membranes which let air through and block water. However, air diffusion through these membranes takes time, slowing down the measurement process.

A&D’s new approach is remarkably simple and effective: By mounting the load cell outside of the housing, the SJ-WP scale achieves a stabilization time of 0.5s or less in combination with IP67 protection (dust tight and water proof up to 1m):

A&D SJ-WP externally mounted load cell

Fast, compact, resistant to harsh environments and easy to clean, A&D’s SJ-WP could be a game changer in the food industry.

You can already find further information on A&D’s website.

Adam Equipment

While I have no information on new products coming in 2014 yet, I was told that Adam is planning to add USB host functionality to a number of balances. This would allow weighing data to be written directly on a memory stick, greatly simplifying data logging and data transfer to a computer. This functionality is already available on Adam’s PMB moisture analyzer:

PMB Moisture Analyser


The first pages of the 2014 catalog show Kern’s continued focus on touchscreen scales. The new models include analytical and precision balances as well as platform scales. While Kern does not indicate who the ODM is, I’m pretty sure these devices are made by Radwag in Poland.

Kern Touchscreen Scales

A cooperation between the two companies would make sense: Kern’s strengths are sales and marketing, while Radwag is good at actually developing and manufacturing weighing instruments.

Further information will soon be available on Kern’s website.


The new Valor 2000 and 4000 are aimed at the food industry and are meant to improve productivity even in harsh environments. There are still some inconsistencies in the available documents but it appears that Ohaus is claiming a stabilization time of 0.5s with an IPX8 rating (no dust ingress protection; protected against submersion beyond 1m).

Ohaus Valor 4000 XW

If you’ve read this post from the very beginning, you might be wondering how Ohaus has been able to achieve this with a load cell that’s placed inside the housing. The answer is called “Flow-Through Design” and simply means that there are indeed some holes in the housing which allow air and liquids to enter and exit relatively unhindered. The electronic components are silicon sealed to protect them from fluids and condensation:

Ohaus Valor 4000 flow through design

I’m looking forward to comparing this approach with A&D’s external load cell solution.

Update March 2014: Ohaus has released a video featuring the new scales:

Smartlux (my company)

I want to take this opportunity to announce that our RS-232 communication software “232key” is going to be released this year:

Rs232 Software

Our software is designed to make it easier to transfer measurement values from any instrument with an RS-232 interface to any application which accepts keyboard input. It receives data from a scale, balance or other device via RS-232 (COM port), extracts the numeric value, formats it and “types” it into another program (“keyboard wedge”-functionality). I’ll announce the release on this blog.