TSO C8b approved. Ascent shall be indicated by a clockwise rotation of the pointer from zero.
Descent is indicated by a counter clockwise rotation.
Zero is at the 9 o'clock position. Stops shall be incorporated to limit pointer movement at the end of the scale. All models are temperature compensated and are provided with a zero adjustment screw located on the face of the case in the 7 o'clock position. How to Apply for a Job Welcome to the PSI Website. You are among the first people to visit our site.