1. Introduction
Thank you for choosing the Taylor Digital Thermohygrometer Model 5566. This device is designed to provide accurate and reliable measurements of both temperature and relative humidity (RH) in various environments such as labs, offices, and storage areas. Its clear LCD display ensures easy readability of current conditions. This manual provides essential information for the proper setup, operation, and maintenance of your thermohygrometer.
Key features include:
- Measures temperature from -58°F to 158°F (-50°C to 70°C).
- Measures relative humidity from 10% to 95% RH.
- Large, easy-to-read LCD display.
- Switchable temperature units (°F/°C).
- Versatile mounting options: wall-mount or desktop stand.
2. Setup
2.1 Unpacking
Carefully remove the thermohygrometer from its packaging. Inspect the device for any signs of damage. Retain the packaging for future storage or transport.
2.2 Battery Installation
The Taylor Digital Thermohygrometer requires two (2) AAA batteries for operation. These batteries are typically included with the device.
- Locate the battery compartment cover on the back of the unit.
- Slide or unclip the cover to open the compartment.
- Insert two AAA batteries, ensuring the correct polarity (+ and -) as indicated inside the compartment.
- Replace the battery compartment cover securely.
2.3 Mounting Options
The thermohygrometer offers flexible placement options:
- Desktop Use: Flip out the integrated stand located on the back of the unit to place it on any flat surface.
- Wall Mounting: Use the keyhole slot on the back of the unit to hang it securely on a wall hook or screw. Ensure the mounting surface is stable.

Image: The Taylor Digital Thermohygrometer, illustrating its compact design and clear LCD display for temperature and humidity readings. The device is shown from the front, highlighting its primary function.
3. Operating Instructions
3.1 Powering On
Once batteries are installed, the device will automatically power on and begin displaying readings. There is no separate power button.
3.2 Display Overview
The LCD screen displays two primary readings:
- Temperature: Shown in a 3.5-digit, 0.75" H format.
- Relative Humidity (RH): Shown in a 2-digit, 0.75" H format.
3.3 Temperature Unit Selection (°F/°C)
To switch between Fahrenheit (°F) and Celsius (°C) temperature units:
- Locate the °F/°C switch or button, usually on the back or side of the unit.
- Press or slide the switch to toggle between the two temperature scales. The display will update immediately.
3.4 Reading Measurements
The device continuously monitors and updates the temperature and humidity readings. For accurate measurements, ensure the device is placed in a location free from direct sunlight, drafts, or extreme temperature fluctuations. The response time for readings is typically less than 1 minute.
4. Maintenance
4.1 Cleaning
To clean the thermohygrometer, use a soft, dry cloth. For stubborn marks, a slightly damp cloth with mild soap can be used, followed by a dry cloth. Do not use abrasive cleaners, solvents, or immerse the device in water.
4.2 Battery Replacement
When the display becomes dim or the readings become erratic, it is time to replace the batteries. Follow the battery installation steps outlined in Section 2.2. Always replace both AAA batteries simultaneously with new ones.
4.3 Storage
If the device will not be used for an extended period, remove the batteries to prevent leakage and potential damage. Store the thermohygrometer in a cool, dry place, away from direct sunlight and extreme temperatures.
5. Troubleshooting
If you encounter issues with your Taylor Digital Thermohygrometer, please refer to the following common problems and solutions:
- No display or dim display:
Solution: Check if the batteries are installed correctly with the correct polarity. Replace both AAA batteries with fresh ones. - Inaccurate temperature or humidity readings:
Solution: Ensure the device is not exposed to direct sunlight, heat sources, cold drafts, or high humidity areas (e.g., directly above a humidifier). Allow the device to stabilize in its intended environment for at least 15-30 minutes. If readings remain consistently off, try replacing the batteries. - Display shows '---' or 'LO/HI':
Solution: This may indicate that the temperature or humidity is outside the device's measurable range. Move the device to an environment within the specified operating range.
6. Specifications
| Feature | Specification |
|---|---|
| Model Number | 5566 |
| Temperature Range | -58°F to 158°F (-50°C to 70°C) |
| Humidity Range | 10% to 95% RH |
| RH Accuracy | ±5% RH from 35% to 75% RH; ±8% RH above 95% RH; ±10% RH below 34% RH |
| Response Time | <1 minute |
| Display Type | LCD (2-digit, 0.75" H for RH; 3.5-digit, 0.75" H for temperature) |
| Battery Type | 2 x AAA Batteries |
| Mounting Type | Wall-mount or Desktop Stand |
| Manufacturer | COLE-PARMER |
7. Warranty and Support
Taylor products are manufactured to high-quality standards. For specific warranty information regarding your Taylor Digital Thermohygrometer Model 5566, please refer to the warranty card included with your purchase or visit the official Taylor website. In case of any issues not covered in the troubleshooting section, or for technical support, please contact the manufacturer or your retailer.





