Rotronic HygroPalm HP31 Handheld Humidity and Temperature Meter

A. Product Overview

The Rotronic HygroPalm HP31 is a compact handheld instrument built for fast, reliable spot checks of relative humidity (RH), temperature, and calculated dew/frost point. It uses a fixed, integrated humidity & temperature sensor, making it a dependable tool for field inspections where quick verification is required. The HP31 features a clear graphic LCD, user-settable audible and visual alarms, USB-Micro connectivity, and HW4 software compatibility for configuration and data download. With a logging interval from 1 second to 24 hours and memory for up to 8,000 records, it supports both quick checks and short-to-medium duration monitoring across HVAC service, building diagnostics, storage areas, and QA validation work.

Key highlights:

• Measures: RH, Temperature, Dew/Frost Point (calculated)

• Range: 0–100% RH, –20 to 70°C (instrument)

• Accuracy (typical): ±2% RH, ±0.3°C

• Logging: 1 sec to 24 h interval

• Memory: up to 8,000 records

• Interface: USB-Micro, HW4 software compatible

• Power: 1 × AA battery

• IP rating: IP40 handheld (non-sealed)

B. Working Principle

The HP31 measures humidity and temperature using its integrated sensor and calculates dew/frost point from the measured values.

1. Sensing: The built-in sensor continuously measures relative humidity and temperature from the surrounding air.

2. Calculation: Using RH and temperature, the instrument computes dew point / frost point as a calculated psychrometric value.

3. Display: Readings are shown on the graphic LCD, allowing quick onsite checks and diagnostics.

4. Alarms: If readings exceed user-defined limits, the HP31 provides audible and visual alarm indications.

5. Logging: When logging is enabled, the HP31 records readings at the selected interval (1 sec to 24 h) and stores them in internal memory (up to 8,000 points).

6. Data Transfer & Configuration: Stored data and configuration settings can be accessed via USB-Micro, using HW4 software on a PC.

C. Why It Is Used

The Rotronic HP31 is used to verify and document humidity and temperature conditions in critical environments where moisture control and thermal stability affect product quality, safety, and equipment performance.

Common reasons to use HP31:

• HVAC inspections and commissioning: Verify RH/temperature performance during maintenance, balancing, and troubleshooting.

• Building diagnostics: Identify humidity-related issues such as condensation risk and dew point concerns in occupied spaces or technical rooms.

• Warehousing and storage monitoring: Check environmental conditions that impact materials, packaging, and shelf life.

• Museums, archives, and preservation spaces: Confirm humidity stability to protect sensitive items.

• QA and validation checks: Perform quick compliance checks and keep downloadable logs for audits, validation, or internal reporting.

• Field inspections: Lightweight, battery-powered design supports routine site visits and service work.

D. Suitable Buyers

The HP31 is suitable for:

• HVAC contractors and service engineers performing onsite inspections and commissioning

• Facility maintenance teams managing building comfort and equipment rooms

• Quality assurance (QA) and validation engineers needing traceable monitoring and downloadable records

• Warehouse and storage managers monitoring environment for product safety and shelf life

• Museums, archives, and preservation teams requiring stable humidity control verification

• Pharma and healthcare facility operators performing routine environmental checks in storage areas

• System integrators and building management professionals supporting RH/temperature diagnostics at sites

FAQ

Q1: What does the Rotronic HP31 measure?
It measures relative humidity (RH) and temperature, and it also shows dew point / frost point as a calculated value.

Q2: Does the HP31 support external probes?
No. The HP31 uses a fixed integrated sensor. For external probes (HC2/HC2A), use the HygroPalm HP32.

Q3: What is the measurement range of the HP31?
RH range is 0 to 100% RH, and temperature range is –20 to 70°C (instrument).

Q4: What is the typical accuracy of the integrated sensor?
Typical accuracy is ±2% RH and ±0.3°C (as specified for the integrated sensor).

Q5: Does the HP31 support data logging?
Yes. It supports logging with a selectable interval from 1 second to 24 hours.

Q6: How many records can the HP31 store?
The HP31 stores up to 8,000 records (1 memory block).

Q7: Can I download data from the HP31 to a computer?
Yes. Data can be downloaded via USB-Micro, and the instrument is compatible with HW4 software.

Q8: Does the HP31 provide alarm indication?
Yes. It supports adjustable audible and visual alarms for high/low limits.

Q9: What power source does the HP31 use?
It runs on 1 × AA battery, making it convenient for field work.

Q10: Where is the HP31 commonly used?
Typical applications include HVAC inspections, facility maintenance, warehousing & storage, museums & archive rooms, and QA/validation checks.