In other words, either the instruments were functioning incorrectly or the pilot and first officer were using their data incorrectly.

That was a far greater distance than the instruments could actually function.

According to the Standing's instruments, it's still functioning.

If the purge air fails, shutters allow the instrument to function for a few days without causing harm.

Due to the simple construction, many mechanics build their own testers and those instruments function perfectly well.

Captain Schettino has said various instruments were not functioning.

The other instruments functioned without fault before the mission formally ended on 1 October 1966 after the power supply had been depleted.

The magnetic field is the heart of the magnetic level gauge - the stronger the field, the more reliable the instrument will function.

We see how all the instruments of the stakeholders which have been constructed over the years - since the Beijing Platform - are functioning well.

When the panel was shaded, the number display faded; when the light fell on it, the instrument functioned again.