If you have worked through all seven calibration steps and the Capture app still shows Calibration Required, the calibration is being rejected rather than not attempted. Almost always this comes down to the surface or to small movements during the process.

Connect the sensor, open Sensor Settings in the Capture app and look at Calibration Status. There are four possible states, and they mean different things:

• Updated & Calibrated — you are done, no action needed

• Updated & Poorly Calibrated — the calibration completed but fell outside acceptable limits, so it needs redoing

• Updated & Not Calibrated — the calibration did not register at all

• Not Updated & Not Calibrated — the firmware needs updating first

Full detail on each state is in Firmware & Calibration Update.

Calibration is measuring the sensor against gravity, so it is far more sensitive to the surface than people expect.

Use a surface that is genuinely level. Many gym benches, platform edges, rubber flooring and plyo boxes are slightly off. A table you have checked, or a windowsill, is usually better than anything in the weight room.

Make sure nothing on that surface is vibrating. A phone buzzing on the same table is enough to void a step. So is knocking the table with your arm or leg while you reach over.

Keep the sensor completely still during each step. Place it, take your hand away, and let it settle before the app records the position.

There are seven positions, and the sensor must sit in the exact orientation shown in each picture in the app. The app will normally prompt you to reposition if the orientation is wrong, but it is easy to have the sensor the right way up and the wrong way round.

Calibration depends on both being current. See How to update your Capture App.

If you are using an athlete level login, the app version requirement applies to you too.

If the sensor was unplugged part-way through a firmware update, it can end up in a state where calibration will not complete.

To clear it, press and hold the sensor button for 10 seconds. You may need to repeat this a couple of times. Then reconnect, confirm the firmware version, and calibrate again.

If you have made two clean attempts on a level, stable surface and the status still shows Poorly Calibrated or Not Calibrated, contact [email protected] with:

• The sensor number, found on the back of the sensor

• The Calibration Status shown in Sensor Settings

• Your firmware version and Capture app version

• The device you are using and its OS version

• A photo of the surface and setup you calibrated on, if you can