Design Incorporating a True Black Globe into a Mobile Housing The SK-181GT measures air temperature, relative humidity and direct/reflected radiant heat via its 40 mm black globe to calculate the WBGT index. Weighing only approximately 70 g, its housing makes professional WBGT evaluation personal and portable.
JIS B 7922:2023 Class 2 and ISO 7243-Based Approach The manufacturer positions the SK-181GT as a mobile heat stress monitor compliant with JIS B 7922:2023 Class 2 for ISO 7243-based WBGT assessments. Black globe, temperature and humidity parameters are evaluated within an integrated measurement chain.
Two Distinct Visual Risk Scales for Sports and Daily Living The display is selectable between the Japan Sport Association 5-tier heat stress scale for exercise and the Japanese Society of Biometeorology 4-tier scale for daily living. The measured WBGT value is thus displayed not only as a numerical reading, but also as a visual risk tier for rapid interpretation in the field.
Active Alerting via Buzzer + LED When the configured heat stress threshold is exceeded, the instrument alerts via an audible buzzer and flashing LED. Alarm behaviour adapts to the risk tier; even if the buzzer is muted, the visual LED warning remains active.
Belt Clip, Carabiner, Neck Lanyard or Tripod Included as standard, the carabiner, belt clip and neck lanyard render the unit wearable for mobile field personnel. For fixed-point measurements, the rear tripod mount enables placement at the appropriate measurement height.
Indoor / Outdoor WBGT Mode and Key Lock Selectable WBGT calculation modes accommodate direct outdoor solar radiation versus indoor/shaded environments. The key lock function prevents inadvertent parameter adjustments during ongoing measurements.
Product Documents
Why SATO SK-181GT?
70 g Mobile Black Globe SystemIntegrates a 40 mm black globe alongside temperature and humidity sensors in a pocket-sized housing, streamlining WBGT monitoring for mobile site personnel.
Instant Risk Tier VisualisationComplements the numerical WBGT reading with a 5-tier bar graph for sports or a 4-tier bar graph for daily living, enabling field teams to interpret hazard severity more rapidly.
Wearable and Stationary DeploymentBelt clip, carabiner and neck lanyard are supplied as standard; also features a tripod mount for stationary environmental assessments.
Active Alarm ManagementAudible buzzer and LED activate upon reaching the set threshold; delivers periodic reminder alarms during prolonged threshold exceedances.
Indoor / Outdoor CalculationAllows selection of the correct WBGT equation for outdoor environments in direct sunlight versus indoor/shaded locations.
Engineered for Extended UsePowered by two CR2032 cells, providing an operating life of up to approximately 6 months based on two alarm events per day.
Product Images and Field Deployment
Wearable Mobile WBGT MonitoringSupplied belt clip, carabiner and neck lanyard allow the unit to be carried on the body, offering a practical form factor for rapid WBGT screening across dynamic working environments.
Representative Environmental Measurement via TripodFor stationary measurements, positioning the instrument at a height of 1.2–1.5 m is recommended in the manufacturer manual. A tripod ensures the black globe maintains an unobstructed line of sight to solar and radiant heat sources.
Clean Interface, Field-Focused ControlsLED alarm, buzzer, tripod mount and user-accessible battery compartment are integrated into a compact housing; the key lock feature minimises accidental adjustments.
Visual Guide Converting WBGT into Actionable Risk TiersDedicated warning scales for athletic activities and daily living accelerate field comprehension of measured values.
WBGT thresholds by metabolic rate in ISO 7243The table on the manufacturer page compares reference limit values from resting state through to very high metabolic rates for acclimatised and unacclimatised individuals.
WBGT Threshold Values and Metabolic Workload
ISO 7243:2017 reference framework: The manufacturer product page details WBGT threshold values according to metabolic activity level and acclimatisation status to hot environments. Permissible WBGT limits vary substantially across resting, light, moderate, heavy and very heavy metabolic rates; a single WBGT value therefore cannot be interpreted uniformly across all job tasks.
Measurement and Standards Approach
Mobile deployment does not replace measurement protocol. Whilst the SK-181GT can be worn by personnel, the manufacturer specifies tripod mounting at a height of approximately 1.2–1.5 m for stationary environmental measurements. In sunny outdoor conditions, the black globe must remain fully exposed to direct sunlight, and ventilation openings must never be obstructed by clothing or other barriers.
Application Areas
Occupational Hygiene and Site ScreeningRapid spot-checking of heat stress across multiple workstations and preliminary screening of high-risk areas.
Sports and Athletic TrainingEasy interpretation in field, camp, and outdoor activities with a 5-level heat stress chart for exercise.
Construction Sites and Outdoor AreasMobile WBGT tracking in open-area tasks where direct sunlight and radiant heat are effective.
Manufacturing and WarehousingPortable checking in hot process environments, confined spaces, and work areas with high temperature risk.
Agriculture and Municipal ServicesRapid evaluation in agriculture, field maintenance, and municipal activities with teams working under the sun for prolonged periods.
Daily Living and Event Management4-level risk chart for daily living; clearer presentation of temperature risk in events, schools, elderly care, and outdoor organisations.
Frequently Asked Questions About SATO SK-181GT
Which parameters does the SATO SK-181GT measure?
Measures air temperature, relative humidity, and radiant heat via the black globe; calculates the WBGT index from these values. Globe temperature is used in the calculation but is not displayed as a separate value on the instrument screen.
What is the primary advantage of the SK-181GT compared to the SK-170GT?
The SK-181GT features a significantly smaller, wearable design weighing approximately 70 g; a carabiner, belt clip, and neck strap are standard. In contrast, the SK-170GT is a classic handheld professional WBGT instrument with broader measurement and display capabilities. The application objective determines product selection.
Can the SK-181GT be used outdoors?
Yes. Different WBGT modes are selected for outdoors and indoors/shade. In sunny field conditions, the black globe must be completely exposed to direct sunlight.
How does the SK-181GT assist in sports areas?
The instrument can display Almost safe, Caution, Warning, Severe warning, and Danger levels in a bar chart based on the Japan Sport Association approach. This provides faster on-site interpretation of the measured WBGT value.
Is tripod use possible?
Yes. There is a tripod mount on the rear of the instrument, and the manufacturer specifies a mounting height of approximately 1.2–1.5 m for stationary measurement.
Technical Specifications
Technical Table
Model / Order Code
SK-181GT / No. 8313-50
WBGT Measurement Range
0.0–50.0 °C
WBGT Accuracy
±2.0 °C (20–40 °C); ±3.0 °C in remaining range
Air Temperature
0.0–50.0 °C; ±0.6 °C (20–40 °C), ±1.0 °C in remaining range
Globe Temperature
0.0–60.0 °C; ±0.6 °C (20–40 °C), ±1.0 °C in remaining range; used in calculation, not displayed separately
Relative Humidity
10.0–95.0% RH
Resolution
0,1
Sampling Interval
Approximately 20 seconds
Standard
JIS B 7922:2023 Class 2; ISO 7243 based WBGT approach
Operating Environment
0–50 °C, below 95% RH, non-condensing; 0.3–3.0 m/s air velocity
Power
2 × CR2032 lithium batteries
Battery Life
Approximately 6 months of continuous operation with two alarm events per day
Dimensions / Weight
60 × 122 × 25 mm; approximately 70 g (including batteries)
Globe
40 mm diameter, ABS resin
Standard Accessories
Neck strap, carabiner, belt clip, key ring, 2 × CR2032
For product selection, application support, tripod/accessories, calibration, and after-sales technical support regarding the SATO SK-181GT mobile WBGT and heat stress monitor, you can contact the NOVEL technical team.
Notice: Technical information on this page has been prepared based on the SK SATO product datasheet, user manual, and the manufacturer's current product page. The manufacturer reserves the right to modify technical specifications without prior notice; verification of current technical data and application conditions prior to purchase is recommended.
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