Which feature helps to reduce parallax error when reading an analog meter?

Which feature helps to reduce parallax error when reading an analog meter?

• A. A mirror or reference mark on the scale to aid eye alignment
• B. Digital display mode only
• C. Automatic backlighting
• D. Wireless data logging

Answer: (A)

Parallax error occurs when your eye isn’t level with the scale, causing the pointer to appear to lie at a different position than it actually is. A mirror or a reference mark on the scale gives you a clear alignment cue so you can position your eye directly in front of the scale. When you look straight at the scale and the pointer, or its reflection, the two lines line up, and you read the correct graduation. That direct alignment is what minimizes parallax, making the reading accurate. Other options don’t fix this alignment issue. A digital display mode would replace the analog read with digits, eliminating parallax but not improving how an analog scale is read. Automatic backlighting helps visibility but doesn’t correct the angle of view. Wireless data logging affects recording data, not the accuracy of reading the scale itself.

Parallax error occurs when your eye isn’t level with the scale, causing the pointer to appear to lie at a different position than it actually is. A mirror or a reference mark on the scale gives you a clear alignment cue so you can position your eye directly in front of the scale. When you look straight at the scale and the pointer, or its reflection, the two lines line up, and you read the correct graduation. That direct alignment is what minimizes parallax, making the reading accurate.

Other options don’t fix this alignment issue. A digital display mode would replace the analog read with digits, eliminating parallax but not improving how an analog scale is read. Automatic backlighting helps visibility but doesn’t correct the angle of view. Wireless data logging affects recording data, not the accuracy of reading the scale itself.