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REED 8778 Heat Stress WBGT Meter

Model: 8778 | UPC: 800837000064

REED 8778 Heat Stress WBGT Meter

Model: 8778 | UPC: 800837000064

Wet bulb globe temperature (WBGT) considers the effects of temperature, humidity and direct or radiant sunlight.

Sorry! This product has been discontinued.

The REED 8778 Heat Stress WBGT Meter has been discontinued, it has been replaced by the REED R6200 WBGT Heat Stress Meter

REED 8778 Offers

This heat stress datalogger measures temperature, humidity, and direct or radiant sunlight with Wet Bulb Globe Temperature (WBGT). With this information, the 8778 determines the "what it feels like" temperature. The 8778 is OSHA recommended and also features a user-adjustable WBGT audible alarm and the ability to adjust settings for indoor temperature measurement.


  • 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
  • In/Out function displays the WBGT value with or without direct sun exposure
  • User selectable unit of measure (°F or °C)
  • Large, easy-to-read LCD display
  • User adjustable threshold alarm (audible)
  • Tripod mount for long-term monitoring
  • Low battery indicator and auto shut off

REED 8778 Specifications

Measuring Ranges Air: 32 to 122.0°F (0 to 50.0°C)
Black Globe: 32 to 176°F (0 to 80°C)
WBGT: 32 to 122°F (0 to 50°C)
Accuracy Air Temperature: ±1.1°F (±0.6°C)
Black Globe (Indoor):
59 to 104°F (15 to 40°C): ±1.8°F (1°C)
Rest of Range: ±2.7°F  (1.5°C)
Black Globe (Outdoor):
59 to 104°F (15 to 40°C): ±3.6°F (2°C)
Rest of Range: ±2.7°F  (1.5°C)
Resolution 0.1°F/°C
Measuring Range 0 to 100% RH
Accuracy 10% to 90% RH: ±3%
Rest of Range: ±5%
Resolution 0.1% RH
General Specifications
Response Time 1 sec
Display LCD
Auto Shut-off Yes (after 10 mins/off)
User Adjustable WBGT Alarm Yes (audible)
Tripod Mountable Yes
Low Battery Indicator Yes
Power Supply 2 AAA Batteries
Battery Life Approx. 1000 hours (Alkaline)
Product Certifications CE
Operating Temperature 0 to 122°F (0 to 50°C)
Storage Temperature 14 to 140°F (-10 to 60°C)
Operating Humidity Range 0 to 95%
Dimensions Instrument: 10 x 1.9 x 1.1" (254 x 49 x 30 mm)
Black Brass Ball Diameter: 2.9" (75 mm)
Weight 4.8oz (136g)

Don't Lose Your Cool. Manage Work Place and Athlete Heat Stress.

Sometimes we only use the air temperature as a measure of how comfortable we will feel when working or playing outside. But when the days get longer and the sun becomes stronger we need to take into account a lot more than air temperature.

Heat-induced illnesses, such as heat exhaustion and heat stroke occur when your body can't keep itself cool. The evaporation of sweat is slowed on hot and humid days causing your body temperature to rise and become ill.

Symptoms of Heat Exhaustion and Heat Stroke

  • Dizziness, Headache, Weakness, Nausea
  • Rapid Heartbeat, Cramps, Chest Pain
  • Labored Breathing, Lack of Sweating
  • Mood changes such as irritability or confusion
  • High fever (104°F and Higher) for Heat Stroke Victims

Preventing Heat Stress

  • Know signs/symptoms of heat-related illnesses; monitor yourself and coworkers
  • Block out direct sun or other heat sources
  • Rest regularly
  • Drink lots of water; about 1 cup every 15 minutes
  • Wear lightweight, light colored, loose-fitting clothes
  • Avoid alcohol, caffeinated drinks, or heavy meals

And most importantly….Monitor the conditions you are in with a Heat Stress Meter
These meters measure how hot it REALLY feels outside when humidity is combined with temperature, air movement and radiant heat.

What is WBGT or Wet Bulb Globe Temperature?
WBGT index is a term used in industry, sports and other areas to indicate the heat stress level for humans and animals. It calculates the heat stress of direct sunlight, which takes into ac¬count temperature, humidity, wind speed, sun angle and cloud cover. This type of meter com¬bines these factors into a single number so you can quickly take into account the conditions you are in.

What is Black Globe Temperature (TG)?
Skin can burn when it comes in contact with exposed machinery, tools and containers left in hot direct sunlight. Black Globe Temperature represents the integrated effects of radiation and wind on these objects.

What's included with the REED 8778

  • Heat Stress Meter
  • Batteries

Ideal Applications for the REED 8778

  • Sports (leisure, organized, and professional)
  • Monitor seasonal conditions to ensure safe environment at school or daycare
  • Ensuring safe work environments

Click on a category to view a selection of compatible accessories with the REED 8778 Heat Stress WBGT Meter.

REED R1500 Tripod

Model: R1500

Expandable up to 56" and features an add-on adapter capable of mounting instruments without a tripod mount. The R1500 is a convenient accessory for any data logging instrument setup for long-term continuous monitoring.

Calibration Lab
When you purchase a REED product it comes included with a one year warranty. We back our products.