We are proud to announce that the product that started it all for us here at GEO PSI has now surpassed 10,000 sold!
Our GEO4-20 105 gauge is synonymous with quality & reliability. It has earned this reputation after serving for over a decade as the go-to downhole monitoring solution for customers around the globe.

Figure 1: 10,000 GEO4-20 Gauge Hero
Humble Beginnings
Back in 2010 our two co-founders Cedric Doerksen and Fred Zillinger set out to provide the oil & gas industry with an innovative downhole monitoring solution which provided reliable real-time data for energy producers. Many had made pressure monitoring tools with direct 4-20 output, but never for an environment as harsh as downhole oil & gas.
With their combined experience and hard work they developed the first ‘A-Series’ GEO4-20 gauge. Brought first to the Australian Coal Seam Gas market, the gauge became an instant success.
Providing users with the accurate & reliable downhole pressure data they needed, all at a cost-effective price point, made for a quick return on investment which encouraged rapid adoption amongst energy producers.
Fast forward to 2023 and the GEO4-20 105 gauge is now one of the most popular downhole gauges on the market. Available in a few different configurations, with over a decade of innovation and refinement behind it, the latest version of our GEO4-20 gauge is now more capable, reliable, and popular than ever before.
Figure 2: GEO4-20 105 Gauge
Innovative Features
Since its first iteration over 13 years ago, our growing team has worked hard to develop innovative technologies and processes to increase the capability of our GEO4-20 gauge.
Given our relentless focus on reliability, our team has innovated a number of unique features to make our gauge easier to install, applicable for a rider range of applications, and more reliable in even the harshest downhole environments. These features have set new standards for downhole gauge quality, and the features pioneered on these gauges have been implemented across many of our other tools.
- Patented Easy-ConnectTM Cablehead
Developed first for our GEO4-20 line of gauges, our patented Easy-ConnectTM Cablehead system greatly increases the reliability of the connection from the gauge to the TEC. It also makes for a more rapid installation of our tools in the field saving valuable time on the rig floor.
- Pressure Testable Design
After further developing our patented Easy-ConnectTM Cablehead system our engineering group added the ability to pressure test the connection. This provides a means of verifying a robust leak-free seal before deploying the tool downhole.
- Leak-Proof Design
Our GEO4-20 gauges feature robust Stainless Steel 316L housing and a fully welded construction. The leak-proof fully welded construction ensures maximum protection against gas and fluid invasion.
- Certified Intrinsically Safe
Exclusive to our pressure-only GEO4-20 105 gauge, it holds an IECEx Ex ia IIB T3 Ga Intrinsically Safe certification.
- Integrated Temperature Monitoring
Our GEO4-20 105 T gauge features integrated temperature monitoring. With the use of the PT6 users can read real-time temperature alongside their real-time pressure data for an added element of critical downhole information.
- Cathodic Protection For High-Corrosion Environments
The unique design of our innovative GEO4-20 CP 105 T gauge enables best-in-class corrosion protection. Featuring a unique electrical design and a sacrificial anode this gauge is designed to survive in the most highly corrosive downhole environments.
Best-In-Class Capability
Aside from its best-in-class reliability, track record, and feature set, our GEO4-20 gauge also offers the highest quality data of any gauge of its kind.
With a high-quality piezoresistive sensor and a finely tuned PCB design our gauge is able to deliver precision data direct to surface in real-time.
With a pressure accuracy of ± 0.1% Full Scale and less than 0.25% Full Scale Drift / Year our tool delivers accurate data beyond what any other 4-20 tool on the market can provide.
The unique capability of our tool provides unprecedented value to our customers making it a go-to solution for producers around the world.
Global Adoption
In just over a decade over 10,000 gauges have been built and installed around the world!
So many that we had a hard time even squeezing 10,000 into the photo below!

Figure 3: Image of 10,000 GEO4-20 Gauges with ReliabilityJob1TM Overlay
With much of our gauges installed throughout Australia, the USA, & Canada, our GEO4-20 gauges have provided immense value to users around the world.
A Legacy Of Reliability
Our GEO4-20 gauges have built a legacy of reliability. Given their robust design, most of the 10,000 gauges we have made are still in use to this day, including some of the first gauges we ever sold!
We are thankful to the many hard-working men and women here at GEO PSI who have been dedicated to the development of this product line. We are incredibly proud of this significant 10,000 milestone, and look forward to continued success in the years to come!
To learn more about our line-up of GEO4-20 gauges you can visit the links below, or reach out to one of our helpful support staff via our contact page.