
Hanna Instruments HI-7638 Submersion Conductivity Sensor, 3 metre
EC/TDS probe, ATC with NTC sensor for immersion installation.
This four-ring in-line probe measures conductivity in industrial applications with a platinum ring and NTC sensor for Automatic Temperature Compensation. With its durable design, you can count on this electrode to stand up to your process environment. EC/TDS probe, ATC with NTC sensor for immersion installations.
In-line Conductivity Probe with Platinum Ring
- Four-ring probes measure conductivity with platinum sensors.
- Built-in temperature sensor for Automatic Temperature Compensation.
- Built for everyday, demanding use in industrial applications.
The HI-7638 is an in-line conductivity probe with colour coded wires and NTC sensor.
The HI-7638 conductivity probe combines the proven four-ring potentiometric method of measuring conductivity with platinum sensors. The universally acclaimed four-ring method provides an exceptionally stable measurement over a wider range. These probes do not suffer polarisation, nor do they need frequent calibration or cell changes.
The built-in temperature sensor for the HI-7638 allows automatically temperature compensated measurements and features easy operation and maintenance.
Key features
- In-line conductivity probe - Suitable for direct immersion in pipes.
- Four-ring method - Provides an exceptionally stable measurement over a wider range. These probes do not suffer polarisation, nor do they need frequent calibration or cell changes.
- NTC sensor - Provide accurate and effective temperature compensation.
- Colour-coded wires - Variety of cable lengths incorporating colour coded wires for easy connection to transmitters.
- Platinum sensor - Provides the best response over a wide range of applications.
PEI body - PEI bodied electrodes are rugged and suitable for non-critical applications that require a very good combination of chemical, mechanical, and thermal resistance.

Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.