In-situ relative humidity sensor for concrete slab testing
The probe that goes into the slab. Complies with ASTM F-2170, the standard method for determining relative humidity in concrete floor slabs using in-situ probes. It can also be used to read ambient conditions.
Compatible meters
- Delmhorst HT-4000
- Delmhorst TotalCheck
Important — fewer meters than the ambient sensor
The RH/T-S3 works with the HT-4000 and TotalCheck only. The RH/T-S1 ambient sensor additionally works with the Navigator Pro and QuickNav, but the S1 cannot do in-situ testing. If you own a QuickNav or a Navigator Pro and you need ASTM F-2170 results, talk to us before ordering — the meter is the limiting factor, not the sensor.
Specifications
| Part number | RH/T-S3 |
|---|---|
| Type | In-situ RH and temperature probe |
| Standard | ASTM F-2170 |
| Also available as | RH/T-S3/5, pack of five |
| Sold as | Each |
What else the test needs
- CS-3 sleeves — the plastic sleeve that lines the drilled hole. Required for the test.
- A rotary hammer and the correct bit for the sleeve diameter.
- Time. ASTM F-2170 requires the hole to equilibrate before the reading is valid — the sleeve is installed, capped and left. A reading taken too early is not a compliant reading.
Why relative humidity and not a surface reading
A resistance or scanning reading tells you about the top few millimetres of a slab. Flooring fails because of moisture deeper in, which migrates up once an impermeable covering goes down. In-situ RH at the correct depth is what flooring manufacturers ask for when a claim is made, and it is the reading that protects you.
Frequently asked questions
How many probes do I need?
ASTM F-2170 sets a minimum number of test locations based on floor area. Check the current edition of the standard for your slab, and buy sleeves accordingly.
Can I reuse the probes?
The sensor is reusable. The CS-3 sleeve stays in the slab.
How do I know the sensor is accurate?
Check it against the RH/TK/33 or RH/TK/75 salt solution kit. On a job where flooring is going down over your reading, do it before you start.
Can I extend it to read the meter more easily?
Yes — the RH/T-C1 gives 3 feet of extension.
Not sure which part suits your meter? Tell us the model and what you are testing and we will confirm the right one before you order.
