Extech HT30 Heat Stress WBGT Meter User Manual

Introduction

The Extech HT30 is a specialized meter designed to measure Wet Bulb Globe Temperature (WBGT), which accounts for the combined effects of temperature, humidity, and direct or radiant sunlight. It also calculates the Heat Stress Index, indicating how hot it feels when humidity, air movement, and radiant heat are considered. The device features a Black Globe Temperature (TG) sensor to monitor solar radiation effects on exposed surfaces and an in/out function for WBGT readings with or without direct sun exposure. Additional functionalities include an Auto Power Off feature with override and a built-in RS-232 interface for data communication.

What's in the Box

• Extech HT30 Heat Stress WBGT Meter
• 2 x AAA Batteries

Setup

Battery Installation

The Extech HT30 requires 2 AAA batteries for operation. To install or replace batteries:

1. Locate the battery compartment cover on the back of the unit.
2. Slide the cover open in the direction indicated by the arrow.
3. Insert the 2 AAA batteries, ensuring correct polarity (+ and -).
4. Replace the battery compartment cover until it clicks securely into place.

Initial Power On

Press the POWER button to turn the meter on. The display will illuminate and show the current readings.

Operating Instructions

Understanding the Display

Front view of the Extech HT30 Heat Stress WBGT Meter, showing the display and control buttons.

The large LCD displays various measurements. The primary reading is typically the Wet Bulb Globe Temperature (WBGT) or Air Temperature (TA), depending on the selected mode. Indicators on the display show the current measurement unit and mode.

Measurement Modes

The HT30 can measure several parameters crucial for heat stress assessment:

• Wet Bulb Globe Temperature (WBGT): This comprehensive measurement considers temperature, humidity, and direct or radiant sunlight.
• Heat Stress Index: Measures how hot it feels when humidity is combined with temperature, air movement, and radiant heat.
• Black Globe Temperature (TG): Monitors the effects of direct solar radiation on an exposed surface.
• Air Temperature (TA): Standard ambient air temperature.
• Humidity: Relative humidity percentage.

The HT30 considers temperature, humidity, and radiant heat for accurate heat stress assessment.

Selecting Measurement Units and Modes

Use the MODE button to cycle through the available measurement parameters (WBGT, Heat Stress Index, TG, TA, Humidity). The display will update to show the selected reading.

The unit allows selection between degrees Fahrenheit (°F) and degrees Celsius (°C). Refer to the full manual for specific button combinations to change temperature units.

The meter features an In/Out function for WBGT readings and selectable units for temperature.

In/Out Function for WBGT

The HT30 includes an "In/Out" function to display the WBGT value with or without direct sun exposure. This is critical for accurate assessment in various environments. Consult the detailed instructions in the complete user manual for how to activate and interpret this function.

The Black Globe Temperature sensor monitors the effects of direct solar radiation on an exposed surface.

Auto Power Off

To conserve battery life, the HT30 is equipped with an Auto Power Off feature. The meter will automatically shut down after a period of inactivity. This feature can be overridden if continuous measurement is required. Refer to the full user manual for instructions on disabling the Auto Power Off function.

RS-232 Interface

The built-in RS-232 interface allows for data transfer to a computer for logging and analysis. Optional PC software is required for this functionality. Consult the software's documentation and the HT30 manual for connection and data transfer procedures.

Maintenance

Cleaning

Wipe the meter's casing with a damp cloth as needed. Do not use abrasive cleaners or solvents. Keep the sensors clean and free from dust and debris to ensure accurate readings.

Storage

When not in use for extended periods, remove the batteries to prevent leakage and damage to the unit. Store the meter in a cool, dry place, away from direct sunlight and extreme temperatures.

Troubleshooting

Specifications

Detailed specifications for the Extech HT30 Heat Stress WBGT Meter.

Physical and Electrical Specifications

• Product Dimensions: 1.6 x 1.6 x 9.4 inches (4.06 x 4.06 x 23.88 cm)
• Item Weight: 4.94 ounces (0.14 kg)
• Batteries: 2 AAA batteries (included)
• Color: Black

Dimensions of the Extech HT30 Heat Stress WBGT Meter.

Warranty and Support

For warranty information, technical support, or service inquiries, please refer to the official Extech website or contact their customer service department. Keep your purchase receipt as proof of purchase for warranty claims.

You can find more information and support resources on the Extech Store on Amazon.