200 years of legal metrology in Luxembourg

Did you know that Luxembourg’s law of August 21st 1816 made the metric system obligatory for all commercial transactions? I didn’t, until I was invited to the 200 year celebration “Bicentenaire de la Métrologie Légale”, which took place in Belval yesterday. The most prominent speaker, Luxembourg’s Deputy Prime Minister and Minister of the Economy Étienne Schneider, took this opportunity to announce that Luxembourg has decided to acquire an atomic clock.

Deputy Prime Minister and Minister of the Economy Étienne Schneider
Deputy Prime Minister and Minister of the Economy Étienne Schneider

Other speakers included ILNAS director Jean-Marie Reiff, BLM director Philippe Kadok, Professor Olivier Francis from the University of Luxembourg and Dr. Martin Milton, director of the BIPM. Mr. Kadok’s presentation contained a slide with interesting facts about the Service de Métrologie Légale: In 2015, this relatively small sub-organization of the BLM verified 2861 petrol pumps and more than 1450 weighing instruments of all types throughout the country.

BLM director Philippe Kadok
BLM director Philippe Kadok

Several organizations with ties to the field of metrology had set up stands in the conference hall. The Service de Métrologie Légale’s stand showcased balances, weights and other measurement instruments. Sadly, recently retired director John Kirchen was nowhere to be seen.

Service de Métrologie Légale
Service de Métrologie Légale
A&D EK-610i balance used for density determination
A&D EK-610i balance used for density determination

Visitors were also invited to take a tour of ILNAS’ recently inaugurated EMC lab (used only for market surveillance purposes, not for product certification).

 

 

Ohaus Scout STX – a touchscreen scale done right

The first scale with a touchscreen display that I ever used (not made by Ohaus) 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:

Ohaus Scout STX Einschaltdauer

Settings

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:

Ohaus Scout STX Sprache ändern

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.

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:

Waage Ohaus Scout STX: Zählfunktion

12 seconds into the video, you can see that the scale displays a numpad 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:

Weighing Plums on an iPhone

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:

iPad Chopping Board (English Subtitles)