ATI TEAS (Test of Essential Academic Skills) Version 7ReadingHard
A technician is calibrating a measuring device using a set of instructions. Step 3 states: 'Adjust the fine-tuning knob clockwise until the indicator needle aligns precisely with the 0.00 mark. Ensure no parallax error by viewing the needle head-on.' What is the primary reason for the instruction to 'Ensure no parallax error by viewing the needle head-on'?
- ATo prevent damage to the delicate needle mechanism.
- BTo obtain an accurate and reliable reading.
- CTo speed up the calibration process for efficiency.
- DTo avoid over-tightening the fine-tuning knob.
Show answer & explanationAnswer & explanation
Correct answer: B. To obtain an accurate and reliable reading.
Parallax error occurs when an object's apparent position changes based on the viewing angle, leading to inaccurate readings. Viewing the needle head-on eliminates this error, ensuring precision.
Why the other options are wrong
- A. Parallax error is a perceptual error in reading, not a physical action that would damage the mechanism.
- C. Taking care to avoid parallax error often takes more time, not less, as it requires careful positioning.
- D. Over-tightening is a mechanical issue related to force, while parallax error is an optical issue related to viewing angle.
Parallax Error
A perceived shift in the position of an object due to a change in the observer's viewing angle, leading to inaccurate measurements.
- Common in analog instruments with needles/scales.
- Eliminated by viewing perpendicular to the scale.
- Crucial for precision in scientific and technical measurements.
Memory trick: Measure Smart: Look Straight, Read Straight!