Inside the PET & CHUM Systems: Tech That Powers Piletest

When it comes to non-destructive testing (NDT) for deep foundations, few companies have earned the level of global trust and industry respect that Piletest has. With nearly three decades of experience designing highly specialized testing equipment, Piletest offers some of the most advanced systems on the market today. Two of their flagship innovations—PET (Pile Echo Tester) and CHUM (Cross Hole Ultrasonic Monitor)—are essential tools for engineers, contractors, and QA professionals involved in pile integrity testing. 

In this in-depth guide, we’ll walk through what makes these systems stand out, how they work, and why understanding their features could transform your testing protocols. 

The Role of Pile Testing in Modern Construction

Pile foundations are hidden from view once constructed, making their quality difficult to assess without proper testing equipment. Piletest’s products are designed to bring visibility into these critical structures by using sophisticated acoustic and ultrasonic technologies. 

Pile integrity testing is not just about identifying defects. It's about confirming whether a pile can safely carry the design load, meets the project’s specifications, and complies with regulations. Poor testing can result in undetected flaws, leading to settlement issues, cost overruns, or even structural failure. 

That’s where PET and CHUM step in. Each system offers distinct advantages depending on the testing environment, project scale, and required level of diagnostic precision. 

Understanding the PET System: Pulse-Echo Testing for Piles

A reliable method using pulse-echo technology to assess pile integrity accurately.

What is the PET?

PET (Pulse Echo Tester) is a low-strain integrity testing system that uses the pulse-echo method to evaluate pile quality. Designed for speed, portability, and field ruggedness, PET is used globally to inspect large numbers of piles efficiently. 

How It Works

The PET system involves a simple but effective process. A small handheld hammer is used to tap the top of the pile. This impact sends a stress wave down the pile shaft. If the pile is sound, the wave will travel to the toe and reflect back in a predictable pattern. If there are defects, changes in material, voids, or other anomalies, they will also reflect the wave—often earlier and with distinct signatures. 

A sensitive accelerometer records these reflected waves and produces a visual waveform (reflectogram) for interpretation. Experienced users can identify changes in wave patterns to determine pile length, quality, and integrity. 

PET Variants: USB and Bluetooth Options

PET is available in two formats: 

• PET USB, which connects directly to a Windows PC/Tablet/Notebook

• PET Bluetooth is designed to wirelessly interface with Android devices, such as tablets or smartphones. It can also connect wirelessly to any Windows PC/Tablet with Bluetooth interface.

Both models share the same robust features and software, giving field teams the flexibility to work in various environments and technology ecosystems. 

Key Features and Benefits

Some of the standout features of the PET system include: 

• IP68-rated casing, ensuring full dust and water resistance.

• No software licensing fees, with unlimited installations and free updates for 10 years.

• Real-time waveform display for immediate feedback.

• High testing productivity—up to 100 piles per hour in favorable conditions.

• Complementary features - such as FFT analysis, signal match auto profiling, and many work efficiency features to reduce test time.

This level of performance makes the PET ideal for large-scale projects where time is critical but quality cannot be compromised. 

The CHUM System: Advanced Cross-Hole Ultrasonic Testing

What is CHUM?

While PET is ideal for rapid screening, CHUM is designed for high-resolution cross-hole testing. It uses ultrasonic wave transmission to detect defects deep within the pile that are not always visible using low-strain methods. 

CHUM is widely used in situations where drilled shafts are deep and slender or large-diameter piles need detailed internal imaging. It goes beyond simple pass/fail testing to provide tomographic insights—essentially “ultrasound scans” of the concrete. 

How It Works

CHUM operates by placing a transmitter probe in one access tube and a receiver probe in another. These tubes must be embedded within the concrete at the time of construction and filled with water for proper ultrasonic transmission. 

When the transmitter emits a pulse, the wave travels through the concrete and is picked up by the receiver. Any voids, honeycombing, or poor concrete quality will alter the speed and strength of the wave, which is captured and displayed in a signal graph. 

Multiple scans across tube pairs at various elevations generate a complete cross-sectional view of the pile. Advanced software then reconstructs 2D or 3D images of the interior using tomographic algorithms. 

What Makes CHUM Unique?

CHUM includes several highly specialized features: 

• Real-time 2D tomography during testing

• Support for 3D image reconstruction for deep analysis

• Multiple testing modes, including Cross-Hole, Single-Hole

• USB connection for ease of use on Windows PC/Tablet or laptop/

• Automatic gain control (AGC) to adjust signal strength dynamically

• High depth capacity, capable of handling pile depths over 150 meters

CHUM offers unmatched clarity and insight into pile conditions. It is especially valuable in complex foundation projects, forensic investigations, and critical infrastructure settings where risk tolerance is low. 

PET vs. CHUM: Choosing the Right Tool for the Job

While both PET and CHUM are pile testing tools, they serve different purposes. Here's how to decide which one suits your project needs: 

Use PET When:

• You need to test hundreds of piles quickly

• The goal is to check basic integrity and length

• You're working on driven piles, precast piles, or similar designs that are not too slender with a Length/diameter ratio below 40.

• Testing conditions are variable (dust, moisture, etc.)

Use CHUM When: 

• You're dealing with large-diameter drilled shafts or very slender piles

• You require internal mapping of defects

• Cross-hole tubes are available for ultrasonic testing

• High-resolution data and tomographic images are essential

In many cases, both tools are used together—PET for general screening and CHUM for targeted diagnosis of questionable piles. 

Software and Usability Considerations

Both systems come with professional-grade software that simplifies interpretation and reporting. Key capabilities include: 

• Real-time signal visualization

• Project management features to group and label piles

• Customizable reporting templates

• Support for multi-language environments

• User-friendly interface, designed to require minimal training

For technical teams and engineers, this software advantage cannot be overstated. The ability to produce accurate on-site reports, interpret data in real time, and easily organize thousands of test results ensures project efficiency and regulatory compliance. 

Durability and Field Readiness

Construction sites are unpredictable. From rain and dust to high temperatures and rough handling, equipment needs to be built to last. Both PET and CHUM are tested rigorously for real-world conditions. Their waterproof, impact-resistant casings are engineered for daily use, even in extreme environments. 

Add to this the fact that Piletest products come with long-term software support, and you’ve got a solution that doesn’t become obsolete a few years down the line. In addition, both come with a 3-year warranty and lifelong support, keeping you and your investment well covered.

Final Thoughts

Choosing a pile integrity testing system is not a decision to take lightly. It's a long-term investment that affects your ability to deliver safe, compliant, and high-quality foundations. Whether you're overseeing a massive infrastructure project or managing routine quality control on construction sites, the PET and CHUM systems offer the performance and reliability you need.

With a focus on precision, ease of use, and long-term support, Piletest continues to lead the way in foundation testing technology. If your goals include improving QA processes, increasing productivity, and minimizing structural risk, it’s worth considering how PET and CHUM can integrate into your workflow. Piletest customers enjoy a complimentary SOS service. SOS stands for Second Opinion Support, to allow you to consult with the Piletest experts when you are in doubt.

Frequently asked questions

What is the PET system used for?

PET checks pile integrity using low-strain impact tests. It's ideal for quickly identifying defects and estimating pile length.

How does CHUM detect internal defects?

CHUM uses ultrasonic waves between access tubes to detect internal flaws like voids or weak zones in concrete piles.

Do I need both PET and CHUM?

Use PET for quick testing. Use CHUM for detailed analysis. Some projects benefit from both.

Is the system easy to use?

Yes. Both systems have user-friendly software and require minimal training to operate effectively.

What kind of reports can I generate?

Both PET and CHUM systems provide automatic, professional reports with clear graphs, test data, and interpretations. Results can be easily exported, shared, and customized to meet project and client requirements..