Measure From The Working Position
With fixed armrest office chairs with unspecified standards, measurements are most useful when tied to actual use. Establish the user's seated position first, then compare armrest height and spacing with the desk opening. Include the underside structure, because an obstruction may matter even when the desktop itself appears clear.
Check the route towards and away from the working surface. Ask the participant to approach the keyboard, turn towards frequently used items and leave the seat. Note where contact occurs and which movement causes it. These observations explain the practical significance of the dimensions you have recorded.
Distinguish Clearance From Arm Support
Passing beneath a desk does not show that fixed armrests suit the person using them. Observe whether the user rests the forearms naturally and keeps the shoulders relaxed during representative tasks. Ask what happens when work changes from typing to writing or another activity that alters the position of the arms.
Record any attempt to compensate for the armrest position by leaning, reaching or changing the seat position. A change may solve one problem while affecting another part of the arrangement. Assess the resulting posture and task access together, rather than judging success only by the disappearance of desk contact.
Ask A Precise Standards Question
Fixed armrest office chairs with unspecified standards have an information gap to resolve. Ask which standard, if any, is supported by the available documentation and which configuration that documentation covers. Do not interpret an unspecified position as a statement that standardisation is absent, or as an implied compliance claim.
Keep the request relevant to the workplace requirements. Record the information received and the questions it answers, along with anything still unresolved. A successful desk trial supplies evidence about that trial's users and conditions; it does not establish a standards position that has not been documented for the chair.

