Designed to stand alone as the industry leader in thermocouple readout performance.

Extreme Temperature Readout Resolution & Accuracy Long Length Performance Environment Rating

GEOXTR-18 Thermocouple Input Card (Hero) GEO PSI

Made For Industrial Applications

Our team has designed the GEOXTR 18pt Thermocouple Input Card from the ground up to be a go-to solution for users requiring a reliable product with an industrial focus. Featuring advanced capability, a Class 1 Div 2 certification, direct RS485 Modbus output, unmatched performance at long lengths, and the ability to operate reliably in extreme conditions, this thermocouple input card sets itself apart from the competition.

Thermocouple Types:  J, K, E, N, R, S, T, B

Standout Features

With 18 unique channels integrated into a single card, the GEOXTR-18 ensures a simple and cost-effective thermocouple input solution for users monitoring multiple data points.

With an industry-leading impedance of >1.2 MOhm the GEOXTR-18 maintains temperature accuracy at lengths suitable for downhole oil & gas applications. Where many cards drift at lengths above 1,000m, our card has been proven to be upwards of 20°C more accurate at lengths exceeding 4,000m.

Our GEOXTR-18 comes ready to work out of the box. While it doesn’t require any on-site calibration, for users looking to monitor performance or take further control of configuration our intuitive GEOXTR Viewer software is included.

A slim compact design and integrated DIN Rail mount makes this easy to integrate into any data acquisition setup.

Convenient RS485 Output makes for easy integration into any SCADA system. The universal compatibility ensures all users can easily take advantage of their data.

Premium components and a clever industry-focused design provides users with the highest quality data possible.

Resolution: 0.001°C
Accuracy: 0.1°C

Designed to work in the hazardous environments found in different industrial environments such as upstream oil & gas, our GEOXTR-18 features a Class 1 Div 2 Groups CD T4 certification.

Designed to work with Type J, K, E, N, R, S, T, & B thermocouples, our GEOXTR-18 is designed to integrate into any number of temperature monitoring applications.

Gone are the days of removing daily or seasonal temperature swings from your data! With an optimized internal design and highly accurate integrated cold-junction measurement, the GEOXTR-18 is able to accurately compensate for ambient temperatures.

Intuitive Design

A convenient design which makes for easy integration into any thermocouple monitoring setup.

A Uniquely Capable Solution

The GEOXTR 18pt Thermocouple Input Card has been engineered to stand alone as the industry leader in thermocouple readout performance. Featuring 18 unique thermocouple input channels, class-leading data resolution and accuracy, and unmatched data accuracy at long thermocouple lengths, this input card is perfect for users demanding reliable performance and maximum value.

Best-In-Class Resolution

With a best-in-class data resolution of 0.001°C, the GEOXTR-18 provides a more accurate picture of temperature fluctuation. As you can see in the graph below when connected to the same thermocouple point the GEOXTR-18 reveals a level of detail far exceeding that of the competing 8pt thermocouple input card. For users demanding the most from their temperature measurement equipment, or those optimizing industrial production off of real-time data, the GEOXTR-18 is the easy choice.

GEOXTR-18 vs Competition Resolution (Web) GEO PSI

Superior Long-Length Accuracy

The GEOXTR-18 was designed with the intent of being a first-of-its-kind solution for long-length thermocouple monitoring. Especially in applications such as downhole oil & gas, long-length data accuracy is critical. The current 8pt card commonly used in the industry can present data errors of over 20°C at lengths of 4000m. This is unacceptable for downhole use or other industrial applications where accuracy is essential for optimization. The GEOXTR-18 maintains its leading accuracy at long lengths presenting data well within the margin of error of any thermocouple.

Superior Long-Length Data Stability

Not only does the GEOXTR-18 provide accurate data at long lengths, but it also maintains data stability which we have thoroughly tested at lengths up to 4,000m (as shown below). The current leading 8pt thermocouple card not only provides data which is off by over 20°C (over 13%), but it is also wildly unstable with a significant number of points spiking and dipping well outside of an acceptable range. This not only presents a major challenge for engineers and automation systems but also destroys confidence in overall readout performance. The GEOXTR-18 however provides accurate, stable, and reliable data you can trust.

Universal Compatibility

Born out of a need for superior thermocouple accuracy at long lengths in oil & gas applications, and designed to be applicable for industrial use around the globe, the GEOXTR-18 features universal compatibility. Designed to work with Type J, K, E, N, R, S, T, & B thermocouples, and featuring RS485 output and direct DIN Rail mounting capability it has been designed to work anywhere, in even the most challenging conditions.

GEOXTR Compatibility GEO PSI

Easy Configuration

Through the use of our intuitive GEOXTR Viewer software customers can easily access a full suite of configuration parameters including the ability to establish communication, log data, and update firmware. This custom software package comes with every GEOXTR-18 and requires a common RS486 to USB cable (not included). And with convenient LEDs on the top of the case users in the field can quickly troubleshoot and verify functionality.

TC18 Software GEOXTR-18 (Web) GEO PSI


Power Supply Voltage

12-24 VDC

Required Power

30mA @ 24VDC

Thermocouple Input Voltage

1 VDC Max

Input Impedance

>1.2 MOhm

Data Output

RS485 Modbus RTU

Operating Temperature

-40°C to 85°C






4.85” / 123.19mm


4.09” / 103.89mm


0.87” / 22.10mm





Number Of Channels


Compatible Thermocouples

J, K, E, N, R, S, T, B


AWG 14-24


Class I Div 2 Groups CD T4


The GEOXTR-18 card uses Modbus over an RS485 connection. We recommend using FTDI’s USB to RS485 Cable to make this connection between PC and Card. The included GEOXTR Viewer software will display and log thermocouple data, as well as allow for the GEOXTR-18 card to be configured. Other Modbus software will easily connect to the GEOXTR-18 card as well, including many SCADA systems.

In concept, a thermocouple wire is sensed with a miniscule amount of current. This results in a completely negligible voltage drop over even long distances. However, many TC Input card manufacturers design their cards with extra features and follow standard input protection schemes. These extra electronics introduce a small amount of leakage current onto the thermocouple which over long distances of 24 awg thermocouple result in voltage drops in the mV range, enough to drastically alter the temperature readings. As a result, many claim that 100ft is the maximum effective length of a thermocouple. Our GEOXTR-18 card however is designed to have as little leakage current as possible, while still maintaining the same features and protections expected of a TC Input Card. This enables us to maintain data accuracy at long lengths where others can deviate by over 20°C.

No, due to the use of premium components the GEOXTR-18 can work within its operating temperature range with nearly indistinguishable temperature error. This means that from season-to-season, or from day-to-night in extreme climates, temperature readings remain reliable. This is contrasted with many cards which struggle to exceed -10°C, and can experience dramatic temperature reading fluctuations based on shifting ambient temperature.

Included in the box is the GEOXTR-18 itself, a paper copy of our Quick look Guide, as well as a USB thumb drive with digital copies of the detailed User Manual, Quick Look Guide, and a copy of our GEOXTR Viewer software. Users must note that in order to connect to the GEOXTR Viewer software they must supply an RS485-USB cable which is not included.

The GEOXTR-18 comes with a detailed user manual that includes a comprehensive list of Modbus configuration settings and register map. For quick reference, the factory settings are:

Default Slave Address – 12
Default Comport Settings – Baudrate 19200, 8bit, No Parity, and 1 Stop Bit

While the GEOXTR-18 is applicable for a wide range of applications, it was designed from the ground up specifically for use in upstream oil and gas. Its Class 1 Div 2 certification and vastly superior -40°C to 85°C operating range means it is designed to perform in extreme environments. And from its design to its long-length capability to its industry-standard RS485 Modbus output, it has been engineered for safe and easy integration into oil & gas applications.

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Offering more than double the number of thermocouple points, 100x the resolution, and 3x better accuracy, the GEOXTR-18 offers unprecedented value.

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