Fluke 961A Temperature and Humidity Data Logger

A. Product Overview

The Fluke 961A is designed for continuous temperature and humidity monitoring in applications where environmental conditions must be recorded, reviewed and documented.

It features a large LCD screen that allows users to check live measurements, minimum and maximum values, alarm conditions, battery level and the number of stored readings without connecting the instrument to a computer.

The built-in sensor measures temperature from minus 30°C to 70°C and relative humidity from 0 percent RH to 100 percent RH. Temperature resolution is 0.1°C, while humidity resolution is 0.1 percent RH.

The logger can store 32,000 sets of measurement data and supports two memory modes. Stop-when-full mode ends recording when the memory is full, while circular logging continues recording by replacing the oldest data.

Recorded information can be downloaded through the built-in USB connection. PDF reports can be viewed directly without additional software, while Excel and TXT exports are available through FlukeLog software.

Key Features

• Built-in temperature and humidity sensor
• Temperature range from minus 30°C to 70°C
• Relative humidity range from 0 percent RH to 100 percent RH
• Temperature accuracy of plus or minus 0.4°C
• Humidity accuracy of plus or minus 3 percent RH between 20 percent and 80 percent RH at 25°C
• Storage capacity of 32,000 data sets
• Adjustable logging interval from 10 seconds to 24 hours
• Direct USB connection
• Automatic PDF report generation
• Excel and TXT report export through FlukeLog software
• Multiple temperature and humidity alarm thresholds
• Immediate, button-operated and timed start modes
• Stop-when-full and circular logging modes
• Password protection for logger settings and data
• IP65 dust and water resistance
• One-metre drop-tested construction
• CR2450 battery with approximately one year of service under specified operating conditions
• FlukeLog configuration software designed to support US FDA 21 CFR Part 11 requirements

B. Working Principle

The Fluke 961A uses an integrated digital sensor to measure the surrounding temperature and relative humidity.

Before starting a monitoring session, the user connects the logger to a computer and configures the required parameters through FlukeLog software. These parameters can include:

• Logging interval
• Total recording duration
• Start mode
• Stop mode
• Temperature and humidity alarm limits
• Alarm delay
• Time zone
• Trip number and description
• Circular logging selection
• Temperature and humidity correction values

Once configured, the logger begins recording according to the selected start mode. It can start immediately after being disconnected from the computer, after the user presses the logging button or at a scheduled time.

During operation, the built-in sensor measures temperature and humidity at the selected interval. Each reading is stored in the internal memory with the corresponding date and time.

When a measured value exceeds the configured temperature or humidity threshold, the logger records an alarm event and displays an alarm indication. It can also use an LED warning to indicate that an out-of-limit condition has occurred.

After monitoring is complete, the logger is inserted directly into a computer USB port. The user can open the automatically generated PDF report or use FlukeLog software for detailed analysis, graphs, statistics and additional export formats.

C. Why the Fluke 961A Is Used

The Fluke 961A is used to create a reliable record of temperature and humidity conditions over a selected period.

Many products, materials and processes can be affected by excessive heat, low temperature, moisture or sudden environmental changes. A data logger helps users identify these changes and verify whether storage or transportation conditions remained within acceptable limits.

The Fluke 961A is particularly useful because it provides:

Continuous Environmental Monitoring

The logger records measurements automatically, reducing the need for repeated manual readings.

Traceable Measurement Records

Each stored reading includes time-related information, allowing users to identify when environmental changes occurred.

Cold-Chain Verification

The logger can travel with temperature-sensitive products in refrigerated vehicles, containers, cooling cabinets and insulated transport packages.

Temperature and Humidity Alarm Monitoring

Configurable upper and lower limits help users identify conditions that may affect product quality or regulatory compliance.

Simple Report Generation

The direct USB connection allows users to obtain a PDF report without installing special software.

Long-Term Data Collection

With storage for 32,000 readings and configurable intervals, the instrument can be used for both short monitoring studies and extended recording periods.

Quality Control and Compliance Support

The logger provides documented records that can support internal audits, quality assurance procedures, transportation verification and controlled-storage documentation.

Protection in Industrial Environments

Its IP65-rated housing provides resistance against dust and water ingress, making it suitable for demanding storage and logistics applications.

D. Suitable Buyers

The Fluke 961A Temperature and Humidity Data Logger is suitable for:

Pharmaceutical Companies

For monitoring medicines, vaccines, samples, raw materials and temperature-sensitive healthcare products.

Cold-Chain Logistics Companies

For recording environmental conditions inside refrigerated trucks, reefer containers, cooler bags and transport boxes.

Food and Beverage Businesses

For monitoring frozen food, dairy products, processed food, beverages and temperature-controlled ingredients.

Warehouses and Distribution Centres

For checking temperature and humidity in controlled storage areas, stock rooms and dispatch locations.

Laboratories

For monitoring laboratory rooms, sample storage areas, refrigerators, cabinets and environmental test locations.

Hospitals and Healthcare Facilities

For documenting environmental conditions in medicine storage areas, laboratories and refrigeration equipment.

Quality Assurance Teams

For collecting traceable records during storage, transportation, product validation and process audits.

Refrigeration and HVAC Professionals

For evaluating temperature and humidity conditions in cooling cabinets, refrigerators, cold rooms and climate-controlled spaces.

Electronics and Manufacturing Companies

For monitoring moisture-sensitive components, production areas, packaging rooms and finished-goods storage.

Museums, Archives and Document Storage Facilities

For monitoring environmental conditions that could affect paper, artwork, records and sensitive materials.

Frequently Asked Questions

1. What does the Fluke 961A measure?

The Fluke 961A measures ambient temperature and relative humidity using its built-in digital sensor.

2. What is the temperature range of the Fluke 961A?

The temperature measurement range is minus 30°C to 70°C.

3. What is the humidity range?

The relative humidity measurement range is 0 percent RH to 100 percent RH under non-condensing operating conditions.

4. What is the temperature accuracy?

The specified temperature accuracy is plus or minus 0.4°C.

5. What is the humidity accuracy?

Humidity accuracy is plus or minus 3 percent RH between 20 percent and 80 percent RH at 25°C. Outside this range, the specified accuracy is plus or minus 5 percent RH at 25°C.

6. How many readings can the Fluke 961A store?

The logger can store up to 32,000 sets of temperature and humidity data.

7. What logging intervals are available?

The logging interval can be configured from 10 seconds to 24 hours.

8. Does the Fluke 961A require software to download reports?

No software is required to read the automatically generated PDF report. FlukeLog software is required for advanced analysis, parameter configuration and Excel or TXT exports.

9. How does the logger connect to a computer?

The Fluke 961A has an integrated USB plug that connects directly to a computer USB port.

10. Can the logger display readings without a computer?

Yes. The LCD screen can display current measurements, minimum and maximum readings, alarm status, stored data points and battery condition.

11. Can temperature and humidity alarm limits be configured?

Yes. The logger supports multiple upper and lower temperature alarm limits, along with upper and lower humidity limits.

12. Does it support scheduled recording?

Yes. The logger supports immediate start, button start and timed start modes.

13. What happens when the memory becomes full?

The user can select stop-when-full mode or circular logging. In circular logging mode, the logger replaces the oldest readings and continues recording.

14. Is the Fluke 961A waterproof?

The instrument is rated IP65, which provides protection against dust and water jets. It should not be treated as a fully submersible instrument.

15. Which battery does the Fluke 961A use?

It uses one CR2450 battery.

16. What is the expected battery life?

The specified battery life is approximately one year when recording at a 15-minute interval at 25°C.

17. Can recorded data be password protected?

Yes. A six-character password can be configured to protect logger data and settings accessed through FlukeLog software.

18. Is it suitable for pharmaceutical monitoring?

Yes. It is suitable for monitoring pharmaceutical storage, cold-chain transportation, medicine warehouses and other controlled environments where temperature and humidity records are required.

19. Can it be used inside refrigerated vehicles?

Yes. The Fluke 961A is designed for cold-chain and warehousing applications, including refrigerated trucks, reefer containers, refrigerators, cooling cabinets and cooler bags.

20. What report formats are supported?

PDF reports can be accessed directly through USB. Excel and TXT reports can be generated through FlukeLog software.