Custom pH Sensors: Should You Extend the Sensor or the Probe?
One of the most common questions we receive at Zimmer Peacock is:
"Can you make a longer pH sensor?"
The simple answer is yes, but whether you should is a different question.
In this article, we'll explain how Zimmer Peacock's unique printed pH sensors are manufactured, why customers often request custom lengths, and why a mechanical extension is frequently the most practical and cost-effective solution.
Watch the Video
A Very Different Type of pH Sensor
When most people think about pH measurement, they picture a conventional glass pH probe. Zimmer Peacock's pH sensors are quite different.
These sensors are:
- Ultra-thin
- Flexible
- Screen-printed onto polymer substrates
- Small enough to fit into applications where traditional pH probes simply cannot be used
The standard sensor dimensions are approximately:
- 26.3 mm long
- 7.2 mm wide
The sensors are manufactured using screen-printing technology, allowing hundreds of sensors to be fabricated on a single production sheet before being individualised.
If you're new to this technology, we recommend starting with our guide:
👉 Getting Started with Zimmer Peacock's Unique pH Sensor Technology
This article provides an excellent introduction to the technology, operation, and practical implementation of our pH sensors.
How Does the Sensor Work?
Like a traditional pH electrode, the sensor measures the potential difference between:
- A working electrode
- A reference electrode
A high-impedance potentiometric measurement is made between these two electrodes, and the resulting voltage is proportional to the pH of the solution.
The underlying electrochemistry is very similar to a conventional glass pH sensor. The primary difference is the compact, flexible, printed form factor that enables entirely new applications.
Why Do Customers Ask for Longer Sensors?
Many applications require the sensing area to reach into:
- Process vessels
- Reaction chambers
- Sample containers
- Flow cells
- Pipes
- Custom instrumentation
As a result, customers often ask whether the printed sensor itself can be made significantly longer.
For example, instead of a sensor that is approximately 26 mm long, they may request a version that is more than 150 mm long.
From a manufacturing perspective, this can certainly be done. However, there are important implications that need to be considered.
The Preferred Solution: Extend the Probe, Not the Sensor
In many cases, a better solution is to use the standard pH sensor and create a mechanical extension.
This can be achieved by:
- Mounting the standard pH sensor at the measurement end.
- Running conductive tracks or wires through a probe body.
- Connecting the working and reference electrodes to the rear of the assembly.
- Sealing and packaging the probe appropriately.
This approach creates a longer probe while maintaining the benefits of the standard sensor design.
Benefits
- Lower cost
- Faster development
- Proven sensor performance
- Simpler manufacturing
- Easier scale-up
- Use of standard inventory
For most applications, this approach provides the same functionality without requiring a custom sensor format.
The Manufacturing Impact of Longer Sensors
The primary challenge with custom-length sensors is manufacturing efficiency.
The current standard dimensions allow approximately 300 sensors to be manufactured on a production sheet.
If the sensor length is increased significantly, the number of sensors that fit onto a sheet decreases dramatically.
For example:
| Sensor Type | Sensors per Sheet |
|---|---|
| Standard Sensor | ~300 |
| Extended-Length Sensor | ~50 |
This reduction means:
- Lower manufacturing throughput
- Higher material costs per sensor
- Increased production costs
- Higher selling prices
In the example above, manufacturing output decreases from roughly 300 sensors per sheet to approximately 50 sensors per sheet, representing about a six-fold reduction in production efficiency.
When Does a Custom-Length Sensor Make Sense?
A custom-length pH sensor may be appropriate when:
- A mechanical extension is not feasible
- The product requires a continuous printed structure
- Space constraints require a unique geometry
- The application demands a specialized form factor
- Production volumes justify a custom manufacturing approach
In these situations, custom development can be the right solution.
Our Recommendation
For the vast majority of applications, we recommend:
Use the standard pH sensor and create a mechanical extension rather than increasing the printed sensor length.
This approach typically delivers the best balance of:
- Performance
- Cost
- Manufacturability
- Scalability
By combining a standard Zimmer Peacock pH sensor with an appropriate probe design, customers can achieve the required reach while maintaining the cost advantages of standard production.
Learn More
If you're considering integrating pH sensing into your product or research project, start with our introductory guide:
👉 Getting Started with Zimmer Peacock's Unique pH Sensor Technology
Contact Us
Have questions about pH sensor customization or a specific application?
👉 https://www.zimmerpeacock.com/contact
Our team is always happy to discuss your requirements and help identify the most practical solution for your project.