A reliable, repeatable solution for large part leak test

    Many manufacturers struggle with leak test station accuracy, cycle time, and Gage R&R, particularly when faced with complex leak test requirements like large volume leak test, variable volumes, multi-cavity parts, low leak rates, and pressure stability. 

    These test scenarios require a precise balance of pressure control, flow range and fill rate to get an accurate reading and meet cycle time requirements, which the Sentinel 3520 delivers. 

    Performing in the most challenging leak test situations 

    • Testing large parts, up to 1000L Large volume leak testing infographic
    • Testing variable volume parts with multiple cavities 
    • Compensating for temperature fluctuations affecting test 
    • Achieving balanced accuracy, cycle time, and Gage R&R 
    Check out the infographic (image, right) to find out six reasons why our customers use the CTS Sentinel 3520 to meet the challenges of leak testing large parts.

    More accurate defect detection using PSV™ software  

    The Sentinel 3520 is controlled by the sigPOD running Sciemetric’s PSV™ (process signature verification) software which measures thousands of datapoints during each test for more accurate pass/fail decisions.  
    This sigPOD controller also allows you to access visualized control charts, histograms and other SPC tools right at the station. Expand your solution to collect, store and analyze data across stations or the plant with QualityWorX and Sciemetric Studio.

    You may click this link to learn more about the Sentinel 3520 through our pre-recorded Webinar: (Sentinel 3520 Leak and Flow Test Webinar)

    Advanced Product Features

    • Patented PID controlled electronic regulators for pressure and flow
    • Fully adjustable control loop settings for electronic regulators
    • Valve-operated calibration port for automatic verification
    • Unit under test (UUT) isolate valve allows complete self-test without any external connection changes
    • Dedicated temperature sensors for advanced temperature compensation capability
    • Pass/fail decisions with digital process signatures (waveforms)
    • Air piloted valves to reduce effects of heat in high flow manifold version
    • Latching valves reduce effects of heat in low volume manifold version


    • Test pressure accuracy: ±0.25 of full scale, best-fit straight line
    • Test pressure resolution: Down to ±0.000,01 psi
    • Flow accuracy:
    • ±1 % of reading when value is >20 % of full scale
    • ±0.2 % of full scale when value is <20 % of full scale
    • Pressure ranges (psig): 12 psig vacuum to 95 psig
    • Flow ranges: 0 to 30 SLPM
    • Volume ranges: 1 cc to 1,000,000 cc
    • Fill rate: 20 SLPM (low volume manifold) to 300 SLPM (high volume manifold)
    Please see the Sentinel 3520 datasheet for full specifications.


    Input power

    • Connector: M12 4 pin T-code plug
    • Supply: 24 V (22 to 26 VDC)
    • Ripple: <250 mV peak to peak
    • Power (Max): 40 W (including all accessories)
    • Power (Typ): 10 W (single channel leak test)
    • Power (Idle): 6 W
    • Inrush current: 5 A for 0.25 s


    • Connector: M12 4 pin D-code socket
    • Data rate: 100/10 Mbps

    External valve interface

    • Connector: M12 8 pin A-code socket
    • Valves: (4×) 2.5 W at 24 V

    Temperature input (×2)

    • Connector: M12 4 pin A-code socket
    • Sensor: 100 Ω Platinum RTD
    • Excitation: 1.25 mA
    • Range: 0 °C to 200 °C
    • Noise: <0.001 °C rms
    • Bandwidth: 10 Hz

    Leak and Flow Test Instrument: Test Types

    Depending on your test needs, the Sentinel 3520 can be configured to meet your requirements for pressure range, flow meter range and flow configuration. The Sentinel 3520 supports the following test types:

    • Pressure/Vacuum Decay: Leak Standard
    • Pressure/Vacuum Decay: ΔP
    • Pressure/Vacuum Decay: ΔP/ΔT
    • Occlusion: Pressure or Vacuum
    • Ramp to Proof: Pressure (Burst Test)
    • Pressure Verify
    • Customizable Pressure / Flow Sequencing
    • Mass Flow (Flow Models)
    • Test Volume Verification (Flow Models)


    • Pressure measurement and control resolution down to ±0.000,01 psi
    • Flow measurement down to ±0.2 % of full scale
    • High flow fast fill up to 300 SLPM
    • Test parts from 1 cc to 1,000,000 cc in volume
    • Helium evacuate and fill
    • Customizable pressure and flow sequencing
    • sigPOD controller equipped with PSV software, using digital process signatures for advanced test analysis
    • Use the sigPOD controller to conduct an additional in-process test such as press-fit, weld or dispense monitoring