iPhone Screenshots


Tension2Go measures the tension frequency and tension of industrial belts from the ContiTech Power Transmission Group – and it's simple, fast, and convenient. Whether it is a matter of initial installation, maintenance, or fault diagnosis, Tension2Go provides field staff, dealers, and end customers with a quick tension check – and is therefore a low-cost addition to the existing range of tension gauges.

Note: The App does not replace a tension gauge.
The most important points in brief

- Measure the basic resonant frequency of the belt by holding your smartphone 10-50 mm above the belt span, causing the belt to vibrate. Using the frequency value, you can determine the tension force of the belt.

- Have the tension force calculated: To do so, simply specify the type of belt and the length of the free belt span in the belt selection dialog. Tension2Go determines the tension of the belt for you.

- For the most precise value, ensure a quiet environment since noises can influence the result. In such cases, simply repeat the measuring process for better results.

What’s New

Version 1.3

Bugfix for iOS 7.1 iPhone 5S

Ratings and Reviews

2.3 out of 5
3 Ratings

3 Ratings

Greg L ,

No app like this will work

Fundamental limitations of the iPhone prevent any app like this from working for all but rare circumstances.

I tried this app while performing research in V-belt tension. Many V-belt setups have a natural frequency of about 35–50 Hz. This is too low for the microphone on any iPhone to be effective. It is also too high for the built-in accelerometer to work well since they max out at 50 Hz and have poor resolution beyond 35 Hz.

I tried Tension2Go on a A47 belt between two 3.2-inch-diameter sheaves where the tension was instrumented at 90.0 lbs. The natural frequency of the belt was known by calculation and measurement with a stroboscope to be 37 Hz, which is an absolute no-man's land for any iPhone and amounts to infrasound (sub-audible) for the built-in sound system.

Multiple tests with the Tension2Go and an iPhone 4S had the software latching onto the only noise it could discern: a 170 Hz overtone generated by the metal portions of the V-belt-operated machine. Given the spurious frequencies, Tension2Go calculated impossibly high tensions that would snap any A-section belt.

The only way an app like this can work is if the “trum length” (the unsupported length of belt between pulleys) being tested is only about the width of a man’s palm; that's not very practical in real-world situations.

Steve 9845248 ,

Perfect for Paramotors!

The problem is it works great on my friends phone, but doesn’t work on my iPhone 7 or iphone10. I think it is because it needs permission to use the microphone and the app is not updated in a long time.


ContiTech Antriebssysteme GmbH
3.6 MB

Requires iOS 5.1.1 or later. Compatible with iPhone, iPad, and iPod touch.


English, German

Age Rating
Rated 4+
© ContiTech Antriebssysteme GmbH


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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