Jingcheng Engineering’s Field Tests Reveal: How Accurate Is the Repeatability of Direct-Pressure Leak Testers?

In the airtightness testing industry, the first question engineers typically ask when purchasing equipment is:

ThisAirtightness TesterWhat is the accuracy?

However, when it comes to 100% inspection on the production line, what is even more critical than accuracy is:repeatable

No matter how high the theoretical accuracy of a piece of equipment may be,If the same product is tested 10 times in a row and yields 10 different results, the test data itself becomes meaningless.TheProducts were deemed "OK" in the morning but "NG" in the afternoon, resulting in the false rejection of good products, an increase in rework, and a corresponding drop in production efficiency.The

Therefore, the international mainstreamAir tightness testing equipmentIn marketing materials, in addition to precision figures, the emphasis is often placed onRepeatability MetricsThe

This article uses a set of real-world test data to verify that:Domestic brand JCGK (Jingcheng Engineering)Direct Pressure Airtightness TesterHow does it perform in terms of repeatability accuracy?

I. What Is Repeatability?

The same product, the same tooling, the same environment,If the results remain consistent after multiple consecutive testsThe

The first measurement was 6 Pa, the second was 50 Pa, and the third was 20 Pa—The equipment has stability issues.The

After more than 10 consecutive measurements, the data consistently remained within a very narrow range—The equipment has good repeatability.The

II. Why Do Production Lines Place Greater Emphasis on Repeatability?

Production lines for new energy batteries, automotive parts, consumer electronics, medical devices, industrial pressure sensors, and other products may inspect thousands or even tens of thousands of items every day.

The consequences of equipment with high volatility are immediate:

The assessment results for the same product vary depending on the time.Good products are mistakenly classified as defective, and defective products are mistakenly classified as good. This results in large-scale rework, soaring costs, and a decline in customer trust.The

Therefore, repeatability is not only a technical metric but also directly affects production costs and quality control.

III. Test Conditions for This Test

Testing equipment: Jingcheng Engineering JCGK Direct Pressure Airtightness Tester

Video Case: Jingcheng Industrial Technology JC-TC-50S Airtightness Testing MachineRepeatability Verification

Test Parameters::

Project	Value
test pressure	10 kPa
Leakage Limit	50Pa
Number of Tests	11 times
Test Subject	The Same Product
Detection method	direct pressure

IV. What is the principle behind the direct pressure method?

The direct pressure method is currently the most widely used method for airtightness testing.

Step 1: Fill the product to the specified pressure, such as 10 kPa.

Step 2: Close the inflation valve to enter the pressure-holding phase.

Step 3: Monitor changes in pressure. If the product is leaking, the pressure will drop more rapidly; if the product is properly sealed, there will be very little change in pressure.Determine whether the product is leaking by measuring the pressure drop.The

V. Actual Measurement Data

History of the 11 consecutive tests conducted this time:

id	Time	Barcode	Test Pressure (kPa)	Leak Rate (ml/min)	Leakage Pressure (Pa)	Testing time	in the end
1	2026-06-29 16:18:51	—	9.770	0	6	19.2	OK
2	2026-06-29 16:19:18	—	9.770	0	7	19.0	OK
3	2026-06-29 16:19:44	—	9.769	0	6	19.5	OK
4	2026-06-29 16:20:07	—	9.768	0	7	18.2	OK
5	2026-06-29 16:20:32	—	9.769	0	6	19.5	OK
6	2026-06-29 16:20:53	—	9.768	0	7	18.6	OK
7	2026-06-29 16:21:16	—	9.768	0	7	19.0	OK
8	2026-06-29 16:21:39	—	9.768	0	7	19.5	OK
9	2026-06-29 16:22:01	—	9.766	0	6	19.5	OK
10	2026-06-29 16:22:24	—	9.767	0	7	19.5	OK
11	2026-06-29 16:22:50	—	9.763	0	6	19.5	OK

Unit Description: Jingcheng Engineering StandardsAirtightness Testerbe in favor ofPressure Drop (Pa) and Leak Rate (ml/min)Multi-unit display. After entering the equivalent volume, the instrument automatically converts the pressure drop value to a standard leak rate, facilitating data comparison and quality traceability across different process scenarios.

Test Results: All passed.

VI. What Do the Data Mean?

The leakage value remains stable in the 6–7 Pa range.

In 11 tests, there were no sudden changes such as 10 Pa, 15 Pa, or 20 Pa,This indicates that the equipment's noise control has remained stable.The

Maximum fluctuation of only ±1 Pa

Maximum value: 7 Pa, minimum value: 6 Pa,The error range is kept within 1 Pa. When it comes to industrial leak testing,This meets the requirements for 100% inspection on the production line.The

What does 1 Pa resolution mean?

1 Pa is approximately one ten-thousandth of 10 kPa. Therefore,Capable of detecting extremely subtle changes in pressure...which is why the actual measurement data consistently shows readings of 6 Pa and 7 Pa, rather than fluctuating significantly.

VII. Why is the equipment from Jingcheng Engineering so stable?

First, high-precision pressure sensors

The sensor determines the device's upper limit—if the sensor itself drifts significantly, even the most powerful software cannot compensate for it.JCGK employs an industrial-grade, high-precision pressure acquisition system; its unique dual-sensor design enables mutual calibration., Once a numerical deviation exceeds the normal range, a fault alert is triggered. The system continuously monitors even minor changes in pressure drop, thereby ensuring the instrument’s stability and the validity of the test data, and ultimately guaranteeing the quality of the tested products.

Second, the autonomous gas circuit control system

The impact of fluid path design on repeatability is often overlooked. Solenoid valve response time, pipe volume, valve body sealing performance, and flow field stability all affect the final test results.Excellentairtightness meterIt’s not just about software algorithms—it’s about the entire pneumatic system engineering.The

Third, the thermal drift compensation algorithm

Air tightness testing essentially involves measuring air, which is affected by temperature, humidity, and atmospheric pressure.JCGK uses a temperature drift compensation algorithm to reduce errors caused by environmental changes., thereby ensuring consistency in long-term testing.

VIII. How does this level compare to imported equipment?

In terms of consistency,JCGK'sairtightness meterIt has already achieved a level of competitiveness on par with leading imported equipment.The

BecauseAir tightness test equipmentWhat truly determines testing capabilities is not the brand name, but rather:Resolution, repeatability, stability, temperature drift control, and long-term calibration capability.

These 11 consecutive tests showed that the leakage value remained stable at 6–7 Pa, with the error controlled within ±1 Pa, meeting the application standards for industrial mass production lines.

IX. How to Choose a Leak Test Solution?

For low-pressure waterproof testing (10–50 kPa), such as Bluetooth headphones, cell phones, smartwatches, and consumer electronics cases; priority should be given toDirect Pressure Airtightness TesterTheLower cost, with accuracy and resolution down to 1 Pa or 0.01 ml/min, and faster testing speedThe

For high-pressure, high-precision testing (300 kPa and above), such as automotive connectors, battery housings, die-cast parts, and valves; priority is given toDifferential Pressure Airtightness TesterTheAccuracy and resolution up to 0.1 Pa or 0.001 ml/min, with enhanced resistance to environmental interferenceThe

Choosing the most suitable—rather than the most expensive—testing solution is the key to the success of a leak test project.

Conclusion

Determining whether aAirtightness TesterYou can’t judge whether something is excellent based solely on the “0.1%F."Figures like that."

Truly valuable data comes from:Repeatability testing.

Precision EngineeringDirect Pressure Airtightness TesterThe results of this test show that:

• Test pressure: 10 kPa
• Leak Threshold: 50 Pa
• Measured leakage value: 6–7 Pa
• Maximum fluctuation: ±1 Pa
• All 11 tests were passed

This repeatable testing capability is already sufficient to meet the needs of the new energy, consumer electronics, automotive parts, and medical device industries, among others.The Demand for 100% Inspection on Production Lines in the Mass Production IndustryThe

If you are evaluating whether a product is suitable for direct-pressure, differential-pressure, flow-based, or other leak detection methods, it is often more important to make a comprehensive selection based on the product’s design, test pressure, target IP rating, and leak standards than to pursue extreme parameter values.Shenzhen Jingchenggongke Technology Co., Ltd.The team at (JCGK) can help you find the testing solution that best fits your needs—not the most expensive one, but the most suitable one.The

Original Statement:this paper was written byShenzhen Jingchenggongke Technology Co., Ltd.Written by the technical team, reproduced with attribution.Data sources: Precision Engineering internal test data and customer cases.