手表为什么需要做密封测试？

A smartwatch contains dozens of potential leak points, including microphone holes, speaker holes, button gaps, the crown shaft, and charging interfaces. Once the seal fails, it can cause motherboard short circuits, circuit corrosion, and sensor failure. IP67/IP68 certification requires 100% air tightness inspection before leaving the factory.

What is the best method for watch sealing test?

For 100% inspection of finished watches before shipment, the negative pressure method (vacuum decay method) is most recommended. The negative pressure method does not apply inward pressure, so it will not crush the screen or electronic components. It uses a reference chamber to compensate for the inherent airflow of speaker/microphone ventilation holes, avoiding false judgments. It is currently the mainstream non-destructive testing solution for smart wearable production lines.

What is the difference between IP67 and IP68 waterproof test?

IP67 indicates brief immersion (1 meter water depth, 30 minutes), corresponding to a test pressure of approximately 10.5kPa; IP68 indicates continuous immersion (depth and duration defined by the manufacturer), corresponding to a test pressure typically of 30~60kPa. Air tightness testing converts the IP rating into equivalent air pressure/differential pressure thresholds and uses leakage rate to determine whether waterproof capability meets the standard.

What is the accuracy of the PLUS X530 differential pressure leak detector?

The PLUS X530 uses 24bit high-precision acquisition, with a differential pressure resolution of 0.1Pa. The test pressure range covers negative pressure -3~-90kPa and positive pressure 3~500kPa. It supports 99 sets of recipe storage and 50,000 data records, and can connect to factory MES systems via TCP/IP+RS232.

Watch Seal Testing Industry Introduction: Smart Wearable Waterproof Testing Solutions-

I. Industry Overview: Smart Wearables Enter the Era of "Waterproofing as Standard"

The global smartwatch/fitness tracker market continues to grow, with shipments increasing by more than 15% annually. Waterproof and dustproof capabilities have become one of the core indicators for consumers when making purchases:

IP68 is now standardSmartwatches in the 500 yuan and above price range commonly claim IP68 waterproofing, and bone conduction watches and outdoor sports watches go even further, making waterproofing a core selling point.
Increasingly complex structuresMicrophone hole, speaker hole, button gap, crown shaft, charging port—one sealing failure and the entire device is ruined by water ingress.
Full inspection at the factory has become a necessity.: Leading brand OEMs now require 100% air tightness inspection on finished products, with a yield target of ≥ 98%.

In this context,Sealing tester, air tightness tester, air tightness leak detectorAs testing equipment shifts from "optional" to "standard" on production lines, the watch sealing test industry is experiencing rapid growth.

II. Why Watches Must Undergo Sealing Tests

💧 Water ingress = scrap

Risk points	Consequences
Motherboard short circuit	Battery failure, data loss, complete unit scrapped
Circuit corrosion	After the waterproof ring fails, moisture penetrates and the PCB oxidizes.
Screen/Sensor Failure	Touchscreen unresponsive, abnormal heart rate/blood oxygen sensor
Certification failed	Cannot obtain IP67/IP68 certification and cannot be launched on the market.

✅ Non-destructive testing is the mainstream

Traditional water immersion testing (immersion test) belongs toDestructive testing: Requires drying after testing, may corrode circuits, and cannot adapt to production line takt time. Air tightness leak testing adoptsClean air non-destructive testing—No contact with the product and no media residue, making it the mainstream solution for smart wearable production lines.

III. Understanding IP Ratings and Test Standards

Grade	Meaning	Corresponding test pressure reference
IP67	Dust protection (level 6) + short-term immersion (1 m, 30 minutes)	≈ 10.5 kPa (pressure corresponding to 1 m underwater)
IP68	Dust protection (level 6) + continuous immersion (manufacturer-defined)	30–60 kPa negative or positive pressure (per manufacturer's standard)

Note:Air tightness testing does not involve direct immersion in water; instead, the IP rating is converted into an equivalent air pressure / differential pressure threshold, and the leakage rate is used to determine whether the waterproof capability meets the standard. PLUS equipment supportssccm / Pa dual-unit display, providing a direct visual reference to the leak standard.

IV. Four Major Pain Points of Watch Sealing Testing

Pain point 1Many micropores, concealed leak points

A smartwatch has dozens of potential leak paths, including microphone holes, speaker holes, button gaps, crown shafts, and charging ports. Micro-seepage hazards are difficult to detect by visual inspection and require 0.1Pa-level high-precision capture.

Pain Point 2Thin-wall housings are prone to crushing damage.

Watch cases are thin and contain touchscreens and flexible circuits, so traditional positive pressure testing can easily crush the screen. NeedNegative pressure test + controllable downward forcefixture solution.

Pain point 3Vent holes must not be blocked.

Speaker/microphone holes must remain breathable (acoustic performance requirement) and cannot simply be blocked during testing; this must be achieved throughReference cavity compensationInherent airflow, avoiding false judgments.

Pain point 4Production line takt time vs. yield rate conflict

Finished-product full inspection demands fast cycle times and low false-reject rates. Traditional methods are either slow or prone to high false-reject rates, driving up rework costs (in the watch industry, rework costs run about ¥80+ per unit).

V. Comparison of Mainstream Sealing Test Methods

Test Principle	Principle Overview	Applicable Scenarios	PLUS Recommended Equipment
Direct pressure method	Direct inflation pressure decay test	Small parts, fast cycle, low cost	D530
Differential pressure method	Compare the pressure differential against the reference chamber.	High precision, anti-interference, universal	X530 / X550A
Volumetric differential pressure method	Differential pressure testing with compensation for volume differences	Finished packaged components, custom-shaped parts	X530-R
Negative pressure method (vacuum decay)	Vacuum evacuation and pressure rise test	Non-destructive testing of electronic finished products (no screen pressing)	X730 / MT100 Vacuum
Flow method	Flow test passed	Vent hole / breather / open air path	P520
Multi-station	Multi-channel parallel testing	Batch production line efficiency improvement	X830

Recommended:Most recommended for full inspection of finished watches at the factoryNegative pressure method:No internal pressurization, so no damage to the screen or electronic components; the earpiece/microphone vents are compensated via a reference chamber to prevent false judgments.

VI. Overall PLUS Watch Sealing Test Solution

Solution architecture: leak detector main unit + servo press-down fixture + line control + MES integration

PLUS provides integrated solutions from standalone units to fully automated workstations:

Test main unit: X530 High-Precision Differential Pressure Leak Detector / X730 Integrated Leak Detection Machine (Core Testing)
Mechanical seal unitServo press-down mechanism, aluminum alloy fixture, silicone sealing jig, press-down force adjustment module
Pneumatic Control Unit: Cylinders, solenoid valves, air source treatment units, high-pressure PU tubing
Electrical Control Unit: Industrial touch screen, PLC, safety light curtain, emergency stop, audible and visual alarm
Data Interaction Unit: MES communication module, standard leak calibration interface, print port

Core equipment: PLUS X530 high-precision differential pressure leak detector

X530 High-Precision Differential Pressure Leak Detector

Parameter item	Specifications
Testing principle	Standard part comparison differential pressure method
Sensor accuracy	24-bit acquisition, differential pressure resolution 0.1Pa
Test pressure range	Negative pressure -3 to -90 kPa; positive pressure 3 to 500 kPa
Recipe storage	99 sets of product process parameters, one-touch switching
Data storage	50,000 local records, CSV export
Communication interface	TCP/IP + RS232, interfacing with factory MES
IO Port	8 inputs / 8 outputs
Certifications & Qualifications	CE EU safety certification, supports CNAS calibration reports

Standard Testing Process

Parameter retrieval: Select the corresponding watch model recipe on the touchscreen, and preset the test pressure, leak standard, and downward pressure.
Material release: Manually or by robot, place the watch into the positioning fixture.
Servo-driven sealing press: The fixture automatically presses down, the system monitors the pressing pressure, and alarms and stops the machine in case of abnormality.
Inflation → Stabilization → Equalization three-stage buffering, eliminating temperature interference
X530 collects differential pressure data, automatically compares it against the leak threshold, and determines OK/NG.
Pass light for qualified parts, red light + buzzer alarm for defective parts, automatic sorting
Automatic data archiving and uploading to the production line system
Fixture lifts, completing a single test cycle.

Applicable Test Scope

Bone conduction smartwatch, Pixel series smart wristwatch, all-metal plastic hybrid watch, waterproof sports watch
Sealing and leak testing for complete watches, watch cases, earpieces, microphones, and charging ports
Incoming material sampling inspection, semi-finished product air tightness testing, finished product full inspection station
Full coverage of IP67, expandable to IP68 high-pressure waterproof test conditions

VII. Application Cases and Performance Data

Case Study: Full IP68 Inspection of Smartwatch Finished Products at Factory (Contract Manufacturer for a Consumer Electronics Brand)

▲ PLUS Leak Detection Equipment (Negative Pressure / Positive Pressure / Differential Pressure Multi-Mode)

▲ Watch sealing test fixture

Indicator	Before modification	After modification (PLUS X730)
Factory pass rate	92%	99.2%
Test cycle time	25s/piece	≤ 12s/piece
False positive rate	3%	< 0.3%
Equipment failure downtime	Average 6 times per month	0 times (continuous operation for 90 days)
Operator	3 operators/line	1 person/line

Key solution:Negative pressure test (-50 kPa) without pressing the screen; the dedicated fixture's sealing gasket avoids buttons and charging contacts; the reference chamber compensates for the inherent airflow of the speaker hole.

VIII. Why Choose PLUS

PLUS (Guangzhou) Intelligent Technology Co., Ltd. has focused on sealing test for over 10 years. Our products include air tightness leak test equipment, air tightness testers, and leak detectors, serving industries such as consumer electronics, new energy, automotive, and medical, with 200+ customer cases.

Focused on sealing testing for over 10 years

From 2018 to the present, we have focused on one thing only—sealing test.
Accumulated 200+ customer cases in the consumer electronics, new energy, automotive, and medical industries.
Watch sealing test is one of the core application scenarios.

In-house developed high-precision sensor module

24-bit high-precision acquisition, matching the accuracy of imported leak detection equipment.
Procurement and maintenance costs are significantly reduced.
The cost-effective choice among domestic leak detectors。

Integrated capabilities from standalone units to complete production lines

Leak detection main unit, servo press-down fixture, PLC control system, and MES integration software are all independently developed and produced in-house.
Single-station and multi-channel fully automatic sealing test equipment can be customized on demand.
Supports scan-code binding with MES, data traceability, fixture control, and automatic sorting.

Complete qualifications

National High-Tech Enterprise(Recognized by the Ministry of Science and Technology)
CE certification for the complete machine
ISO Certified(Chinese and English bilingual version)
15 utility model patents + 3 software copyrights

Improve after-sales service

2-year warranty on the complete machine, 3-year warranty on the sensor.
24-hour on-site technical support in South China.
Standard leak orifice calibration, annual scheduled maintenance, and accuracy calibration support services.

9. Industry Trend Outlook

IP68 goes mainstream in the mid-to-low-end segment: Waterproofing has evolved from a flagship selling point to a standard feature across all price tiers, driving continuous growth in testing demand.
Accelerating Domestic SubstitutionSelf-developed 24-bit sensor module enables domestic leak detectors to match imported ones in accuracy while significantly reducing costs
Automated full-line deliveryMulti-station parallel operation, robotic loading and unloading, and servo press-down control have become the mainstream configuration of production lines.
Digital traceabilityMES integration, real-time data upload, and scan-to-bind have become mandatory requirements that brand manufacturers impose on suppliers.

Watch Seal Testing Industry Introduction: Smart Wearable Waterproof Testing Solutions