Q: What are the dimensions of the Digital Protractor / Level ND-81?
Approximate dimensions: 6-1/4" x 2-1/2" x 1-1/4"
Q: Does this Digital Protractor / Level ND-81 come with a calibration certificate?
No, the box only includes the unit, two batteries, and the instruction sheet. The instruction sheet does include details on how to calibrate the unit once you receive it.
Q: Will this work on the horizontal plane, for example to check rudder travel?
Unfortunately not. It will only work with the horizontal flight control surfaces (ailerons, elevator, etc).
Q: Can you tell me the manufacturer of the ND-81 digital protractor?
The manufacturer of this unit is Nav-Data.
Q: How long do they stay on, Ours times out after 5 minutes. Is there an adjustment to stay on longer?
The 5 minute shutoff is a battery saving feature and cannot be adjusted.