Protimeter HygroMaster L with Quickstick
The Protimeter HygroMaster L is a handheld thermo-hygrometer for professionals. It measures relative humidity, air temperature, dew point and specific humidity, with a replaceable humidity and temperature sensor. It is the lighter-featured version of the HygroMaster 2, built for spot readings of air condition.
This version ships with the short Quickstick, the fast-response sensor covering the full 0% to 99% RH range. It is the general-purpose choice for restoration and building survey work, and the only one of the two sensors that reads below 30% RH.
What is in the box
- HygroMaster L instrument
- Short Quickstick humidity sensor (POL8751)
- Soft pouch
- Instructions
- 9 V battery
Applications
- Flood and water damage restoration
- Building survey and dampness diagnosis
- Ambient condition monitoring during drying
- HVAC test and measurement
HygroMaster L or HygroMaster 2?
Both instruments use the same humidity sensors, share the same accuracy figures and are the same size and weight. The L is the lighter-featured model, and the difference is what it does not do.
| HygroMaster L | HygroMaster 2 | |
|---|---|---|
| Relative humidity, air temperature, dew point, specific humidity | Yes | Yes |
| Infrared surface temperature with laser pointer | No | Yes |
| Plug-in surface temperature probe | No | Yes |
| Surface proximity to dew point | No | Yes |
| Unattended data logging and PC download | No | Yes |
Choose the L if you take spot readings of air condition and record them yourself. Choose the HygroMaster 2 if you need to leave the instrument recording, or if you report surface temperature against dew point — which is the measurement that tells you whether a surface is about to attract condensation.
Hygrostick or Quickstick
The instrument takes two interchangeable sensors and they are not equivalent.
| Hygrostick (POL4750) | Short Quickstick (POL8751) | |
|---|---|---|
| Humidity range | 30% to 98% RH | 0% to 99% RH |
| Below 30% RH | Will not read | Reads to 0% |
| Best for | Sustained high humidity, equilibrium RH in concrete, harsh environments | General ambient work, fast spot readings, drying verification |
| Response | Slower, stable under prolonged wet conditions | Fast |
If you are verifying that a structure has finished drying, ambient readings often sit below 30% RH and a Hygrostick will not report them. If you are leaving a sensor in a sleeved hole in a slab, the Hygrostick is the sensor built for it. Both are consumables: buy Hygrosticks singly or in a 5 pack, and Quickstick ST sensors singly.
Specifications
Taken from the HygroMaster L instruction manual, INS7750L/51L Rev D.
| Measures | Relative humidity, air temperature, dew point and specific humidity (mixing ratio, g/kg or GPP) |
|---|---|
| Hygrostick (POL4750) | 30–40% RH ±3% at 20°C; 41–98% RH ±2% at 20°C. Temperature −10°C to 50°C ±0.3°C |
| Short Quickstick (POL8751) | 0–10% RH ±3% at 25°C; 10–70% RH ±2%; 70–99% RH ±3%. Temperature 0°C to 50°C ±0.5°C |
| Operating conditions | 0°C to 50°C, 0–95% RH non-condensing |
| Power | 9 V alkaline battery |
| Size | 177 × 80 × 38 mm |
| Gross weight | 182 g (instrument only) |
| Regulatory compliance | CE, RoHS, ETL |
| Warranty | 24 months on the instrument. Excludes wear on accessories and consumables |
Frequently asked questions
Does it measure moisture in timber, plaster or concrete?
No. This is a hygrometer, not a moisture meter. It measures the air, not the moisture content inside a material. For material moisture you need a pin or non-invasive meter such as the MMS3.
Can I use it for ASTM F2170 concrete testing?
Yes, with a Hygrostick, an extension lead and sleeves. The hole still has to be drilled, sleeved and left to equilibrate. The instrument alone is not enough.
Can I add a surface temperature probe later?
No. Surface temperature, infrared and dew point proximity are HygroMaster 2 functions and cannot be added to the L. If you need them, buy the 2.
How often should it be calibrated?
Twelve months is a sensible starting interval, adjusted to your own work and quality procedures. Humidity sensors are replaced rather than recalibrated; conformance certification for the instrument is available in Australia.
The reading is slow to settle — is it faulty?
Usually not. A Hygrostick is deliberately slow and stable and can take considerable time to equilibrate, particularly moving from a wet environment to a dry one. Fast spot readings are what the Quickstick is for.
Care and maintenance
- Treat humidity sensors as consumables — replace rather than attempt to recalibrate
- Remove the 9 V battery before extended storage
- Retrieve a Hygrostick once its reading has stabilised rather than leaving it in a saturated hole indefinitely
- Clean with a dry cloth only; no solvents on the display or the sensor
Documents
- HygroMaster L instruction manual (INS7750L/51L Rev D, September 2024)
- HygroMaster L datasheet (AAS-920-755C, September 2024)
Not sure whether the L or the HygroMaster 2 suits the work you do, or which sensor you need? Contact Carpet Cleaners Warehouse before ordering and we will confirm the right configuration.
