Salt solution test kit for checking humidity sensor accuracy at 33 per cent
A sealed bottle in which a saturated salt solution holds the air at a known relative humidity. Put the sensor in, let it stabilise, and compare what the meter says with what the kit maintains.
Fitment
- Checks the RH/T-S1 ambient sensor
- Checks the RH/T-S3 in-situ sensor
Specifications
| Part number | RH/TK/33 |
|---|---|
| Nominal humidity | 33% RH, +/- as stated by Delmhorst |
| Method | Saturated salt solution in a sealed bottle |
Why check at two points
A single check tells you the sensor is right at one humidity. Sensors drift with a slope, not an offset, so a sensor that is accurate at 33 per cent can still be reading badly at 75. Checking at both ends is how you find that out. The RH/TK/75 kit is the other half of the pair.
This matters most in restoration and flooring, where the humidity reading feeds a psychrometric calculation or an ASTM F-2170 result that someone else will rely on.
Frequently asked questions
How long does the check take?
The sensor needs time to equilibrate inside the bottle. Set it up and leave it — a rushed check is worse than none, because it produces false confidence.
Does this calibrate the sensor?
No. It verifies it. If the sensor is out, it needs replacing or returning to Delmhorst — the kit tells you which.
Does temperature affect it?
Yes. Salt solutions hold a nominal humidity at a stated temperature. Do the check in stable conditions, not in a hot vehicle.
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.
