Connected Product and Service Design · Study deck

Device Form Factors: Context and Review Evidence

A device may fit the bench and still fail in a wet, gloved, or shared space.

UX Uma is your guide for this deck.

form-factor-reviewenclosure-designmounting

UX Uma, the module guide, in a scene from this chapter.

After studying this chapter

Learning objectives

You will be able to:

Build a form-factor review from deployment evidence.
Test access, mounting, and handling needs in context.
Explain: The cross section puts the antenna keepout beside the board and battery space, so radio needs cannot be assessed apart from enclosure size.
Explain: Material choice affects durability, radio performance, heat, weight, feel, sealing, and serviceability.

Major section

Form Factor Review Path

The cross section puts the antenna keepout beside the board and battery space, so radio needs cannot be assessed apart from enclosure size.

The sensor opening and ingress path show where rain, dust, condensation, or cleaning may reach the unit.
A service opening and mount then determine how an installer can replace a battery without undoing the protection.

Major section

Materials And RF Boundaries

Material choice affects durability, radio performance, heat, weight, feel, sealing, and serviceability.

Metal may be useful for heat or strength, but it can block wireless signals if the antenna is inside the metal boundary.
Soft materials may help wearables or impact protection, but they can create cleaning, aging, or tolerance issues.
The record should show which tradeoff was accepted.

Major section

Ingress And Environmental Protection

Ingress protection is a design decision, not a decorative rating label.

The reviewer should connect the rating or protection strategy to the actual exposure.
The evidence should match the exposure that the device is expected to face.
Vibration, impact, and mounting loads reproduce physical service, while electromagnetic tests cover both emissions and immunity.

Outdoor sensor environmental test record links installed moisture and ingress exposure to a repeatable setup, severity, duration, retained results, and a release decision.

Major section

Mounting And Maintenance

Mounting is part of the user experience.

A device that requires the wrong tool, surface, angle, or permission can fail before it starts collecting data.
The correct choice depends on the deployment and maintenance evidence, not on which method is easiest to draw.
Orientation also matters when the sensor or antenna must face a particular way.

Sensor mounting methods comparing adhesive, screw-mount, DIN-rail, and magnetic installation options.

Major section

Interaction Surfaces

Physical interaction should be simple enough for installation and routine use.

The device should communicate enough state for the person at the device to know what to do next.
A status only task may need a simple LED, while fixed numbers or icons may suit a segment display.

Display technology selection for LED indicators, segment LCD, E-Ink, LCD or TFT, and OLED.

Major section

Worked Review: Outdoor Sensor

A soil or weather sensor is planned for an exposed outdoor location.

The sensor opening and orientation are defined.
Battery replacement or service access is documented.
The antenna path is not blocked by the enclosure, mounting post, soil, or nearby metal.
The validation record includes both bench checks and a placement trial.

Major section

Worked Review: Wearable Tag

A wearable tag is planned for repeated body contact and daily movement.

The black sensor enclosure and the clothing neckline make placement, orientation, and body contact visible rather than hypothetical.
Strap, clip, or attachment method fits the body location and use duration.
Cleaning and sweat exposure are included in the material and seal review.

This body-worn sensing device shows why a wearable-tag review must include clip position, pressure points, orientation, privacy, and whether daily movement can dislodge or obscure the sensors.

Major section

Worked Review: Wearable Tag (continued)

That arrangement shows why a bench-sized enclosure is not enough evidence: the form-factor record must also cover stable attachment, sensor exposure, pressure, clothing movement, and a service path the wearer can manage.

Status feedback is visible or felt without forcing frequent phone checks.
Charging or battery replacement does not make routine use impractical.
Comfort, attachment, cleaning, and status feedback are part of the form factor evidence.

Major section

Form Factor Record

Envelope and material fields then make room for the board, battery, antenna, sensor, and thermal limits.

Ingress and mounting fields ask how seals, openings, surface conditions, and removal will work after installation.
Interaction covers the status or controls a person can reach.
Decision and change condition: accepted design, owner, known limit, open issue, and condition that requires another review.

Deck summary

Key takeaways

The cross section puts the antenna keepout beside the board and battery space, so radio needs cannot be assessed apart from enclosure size.

Material choice affects durability, radio performance, heat, weight, feel, sealing, and serviceability.
Ingress protection is a design decision, not a decorative rating label.
Mounting is part of the user experience.
Physical interaction should be simple enough for installation and routine use.

Retrieval practice

Recall check

UX Uma says: answer from memory, then check your reasoning.

Q1A connected device design uses a metal enclosure with an internal antenna. The record says the enclosure is durable, but it does not show RF evidence from the installed orientation. How should the team assess the enclosure choice before approval?

AAccept metal durability as proof it cannot hurt internal antenna signal.

BApprove CAD alone and leave installed radio tests until firmware work.

CHold until installed RF is tested with metal case, antenna and mount.

DReplace RF measurements with a larger battery and thicker metal wall.

Show answer

Answer: C A form factor decision is reviewable only when physical choices are tied to deployment, RF, mounting, interaction, and validation evidence.

Print reference

Answers

Answer key.

C · A form factor decision is reviewable only when physical choices are tied to deployment, RF, mounting, interaction, and validation evidence.