Kyoto Electronics Manufacturing KEM WBGT Series User manual

CN131
WBGT-301 WBGT-302
WBGT-301WBGT-301
WBGT-302WBGT-302
ISO 7243
Ergonomics of the thermal environment
JIS B 7922
Electronic Wet-bulb globe temperature index meter
- in conformity with Class 1.5
WBGT MeterWBGT Meter
For assessing the risk of Heat StressFor assessing the risk of Heat Stress

WBGT stands for “Wet Bulb Globe Temperature”, an index for predicting heat exchange between the human body
and the environment to understand the risk of heat stress. The index is calculated based on the relative humidity, air
temperature and radiant temperature of the environment and can be ascertained in both indoor and outdoor settings.
The WBGT index is widely applied in heat stress risk assessment, with its standards for measurement being outlined by
bodies such as the ISO and JIS.
What does “WBGT” mean?
Calculation of WBGT
WBGT values are calculated automatically by WBGT-300 series instruments according to the following formulae:
Assessing heat stress risk is quick & easy
with the WBGT-300 series meters
Acceptable Physical Work Intensity By WBGT*1
Heat Stress Prevention Guidelines For Exercise
Cancel All Exercise Outside special circumstances, all exercise and sporting activities should be canceled, especially those
involving children.
Strong Caution
(cease strenuous exercise)
The risk of heat stress is high, so refrain from activities that easily raise body temperature such as
strenuous exercise and endurance training. Rest and replenish fluids and electrolytes every 10-20
minutes. Persons with higher sensitivity to the heat*1are to lighten or cease activities.
Moderate Caution
(take periodic rests)
Heat stress risk increases in this range, so be assertive in taking periodic rests and replenishing fluids and
electrolytes. For strenuous exercise, rest every 30 minutes.
Low Caution
(proactively replenish fluids)
Death due to heat stress becomes possible from approximately WBGT 21°C.
Stay mindful of indicators of heat stroke and replenish fluids and electrolytes.
Safe Conditions
(replenish fluids when needed)
Under normal conditions, the risk of heat stress is low, but make sure to replenish fluids and electrolytes.
Heat stress can still occur in participants of non-professional “Public” marathons, so exercise caution.
Formula for environments exposed to sunlight
WBGT= 0.7Tw + 0.2Tg + 0.1Td
Tw = wet bulb temperature Tg = globe temperature Td = dry bulb temperature (ambient air temperature)
Formula for environments not exposed to sunlight
WBGT= 0.7Tw
+ 0.3Tg
WBGT °C
31
28
25
21
Category Example Physical Activities By Intensity Level
(Categories 0-4)
WBGT °C
Heat
acclimated*2 Not heat acclimated
0: At Rest At rest, sitting in comfort ≤ 33 ≤ 32
1: Low
Metabolic Rate
Light manual labour (e.g. writing, typing, drawing, sewing, bookkeeping, etc.); labour using arms and
hands (e.g. use of small pliers, physical inspection, assembly, sorting light materials, etc.); labour using
arms and legs (e.g. operating a vehicle under normal conditions, footswitch and pedal operation, etc.).
Drilling small articles while standing; milling machine operation (small articles); coil wrapping (including
for small armatures); machine operation requiring light physical force; walking at or below 2.5km/h on
level ground.
≤ 30 ≤ 29
2: Medium
Metabolic Rate
Continuous hand and arm movement (e.g. hammering, filling ground, etc.); arm and leg movement
(e.g. driving a truck off-road, operation of a tractor or construction vehicle, etc.), use of arms and torso
(e.g. pneumatic hammer operation, tractor assembly, plastering, intermittent moderate lifting work,
weeding, harvesting produce, etc.); pushing and pulling a wheelbarrow or other cart type with a light
load; smithing/forging; walking between 2.5-5.5km/h on level ground.
≤ 28 ≤ 26
3: High
Metabolic Rate
Use of arms and torso with high intensity (e.g. carrying heavy objects, using a heavy hammer, shoveling,
sawing, planing or chiseling hard wood, mowing, digging, etc.); walking between 5.5-7.0km/h on level
ground. Pushing and pulling a wheelbarrow or other cart type with a heavy load, grinding metal, and
stacking concrete blocks.
≤ 26 ≤ 23
4: Very High
Metabolic Rate
Working at a very high intensity (e.g. swinging an axe, shoveling heavy loads/digging hard ground,
climbing stairs); running on level ground at 7km/h or faster. ≤ 25 ≤ 20
Adapted from “Table 1-1: Outline of basic measures for preventing heatstroke in the workplace” published by the Ministry of Health, Labour and Welfare (Japan) and
“Table of WBGT Heat Stress Index Reference Values” appearing in Appendix A of JIS (Japan Industry Standards) Z 8504, inserting concrete examples of physical activities
in place of metabolic rate data.
*1 This table intends to provide a reference for the maximum allowable WBGT for di󱐯erent work intensities to prevent heat stress.
It is not a guarantee of safety, so always consult your physician and workplace health and safety o󱐰cer to best understand individual risks in your work environment.
*2 “Heat Acclimated” refers to persons that within one week prior to assessment were deemed to be acclimated to working in an equivalent or harsher thermal
environment to that used in the test.
Adapted from content appearing on the o󱐰cial Japanese Sports Association website
*1 Persons who are obese, have a below-average tolerance of typical outdoor heat, and/or have low physical endurance

In 1993, before “Heat Stress” was a widely known term in Japan, KEM launched its agship WBGT Meter. Since then,
KEM has been constantly developing and rening the WBGT Meter into a feature-rich, compact solution that is
lovingly adopted by a large number of customers today.
The WBGT-300 series meters conform to the Japanese national industrial standard “JIS B 7922” (measurement of WBGT
with a digital analyser), with the performance of a “Class 1.5” instrument.
The WBGT-301 is endorsed by the Japan Sport Association, a public interest foundation that contributes heat stress
prevention advice nationwide, while the WBGT-302 has earnt an ongoing sales partnership with the Japan Industrial
Safety and Health Association. With a reputation of providing innovative and reliable products acknowledged by
numerous research institutions and other organizations, we hope that you consider making the WBGT-300 series
meters your new partner in heat stress prevention!
While instances of heat stroke are common under the blazing sun or in specic work environments, it can also strike in
non-air-conditioned gymnasiums, working kitchens, bathrooms, and even a󱐯ect infants in strollers. Elderly persons are
at particular risk of heat stroke due to a natural decline in their body's water content and a slower and less productive
sweating response. Special attention needs to be paid to infants and toddlers when placed on the ground, because
their entire bodies bear the brunt of ground-reected heat causing considerably fast and severe heat transfer leading
to heat stress and death.
Buy from a trusted brand, KEM
Heat stress can strike in a variety of settings!
Helping to prevent heat stress in...
Schools Sporting Events
Concerts &
Other Large Events Farms
Care Establishments
Working Kitchens Factories
Family Outings
Construction Sites

WBGT Alarm
The instrument has an audible
alarm that activates when the
WBGT exceeds 28°C.
The WBGT alarm value can be
set between 15°C and 40°C.
Designed For Indoor & Outdoor Use
While standard thermometers can measure ambient
air temperature, they can’t comprehensively analyse
radiant heat like the WBGT-300 series meters can.
Thanks to their globe, all sources of radiant heat are
measurable whether indoors or outdoors. This is
important for better assessing heat stress risk, as the
intensity of solar radiation, ground-reected heat
and heat generated by machinery and workers, for
example, are also determinable.
The memory function is responsible for recording
measurement data over user-set intervals. The interval
between each reading can be set to between 1 and
999 minutes, and up to 30,000 readings can be stored
on the device. Stored data can be transferred to a
personal computer.
High Performance, Compact Design
Even at a compact size, the
WBGT-300 series meters boast
JIS Class 1.5 measurement
performance, delivering highly
reliable WBGT data via high
precision sensors.
Water-Resistant, Low-Maintenance Sensor
Outstanding Responsiveness
The globe of the WBGT-300 series
is of metallic construction with
superb heat conductivity.
Thanks to its industry-leading
compact size (30mm), it boasts
superior response times.
KEM’s WBGT meters have IPX5 water-
resistance, for peace of mind in the
event of sudden rain. Even if the sensor
gets wet, simply wiping or airing it
dry will restore its function. Users can
easily access the robust sensor for
routine performance checking*.
Memory
*make sure to follow the user manual’s instructions
IPX5
Features

USB Connection
eco Mode
RH: Relative Humidity (%)
Ta: Ambient Temperature (°C)
Tg: Globe Temperature (°C)
WBGT Reading (°C)
measurement without sunlight
UART Connections
Globe
Power ON/OFF Button
Temperature/
Humidity Sensor
Strap Attachment Hook
*Note: strap not included
USB Port (Type C)
Setting Button
Tripod Head Mount Thread
Sensor Cap B
Large, Easy-To-View Screen
The WBGT is displayed prominently on
a large LCD screen alongside humidity
& other temperature values, reducing
the need to cycle through screens.
The display’s layout is customizable.
Measurement data can easily
be collated and transferred
to a PC using the USB port.
The instrument can be powered via
the USB port, so you don’t have to
worry about running out of power
when using it for a long time.
UART Communication Mode can be set via a switch
located in the battery port. Using a USB Type C to
RS232 connector & cables allows you to connect to
peripherals such as a warning light, LCD display board
etc.
*Cables & peripherals not sold by KEM
*Please refrain from powering the instrument via USB during rain.
Part Names and Functions
Displayed when eco mode is active. If the
instrument is left unoperated for 20 minutes,
eco mode will turn it o󱐯.
*Please refrain from powering the instrument
via USB during rain.
Hold down for
2 seconds to access
the settings menu
Measures the globe
temperature (Tg)
Holding down the Power
ON-OFF button for 3
seconds turns the device
on and automatically
starts measurement.
Results are updated every
second. Thread for securing to a tripod head
mount and the Wall Mounting Bracket
Measures atmospheric temperature (Ta)
and relative humidity (RH)
For connecting to PC or
supplying power
Can be removed to access the
Temperature/Humidity Sensor
measurement with sunlight

Lineup
Operation examples
When measuring in hand, keep it
as far away from your body for best
accuracy.
Attaching a strap and securing it to
your wrist will prevent it dropping
to the ground.
The Wall Mounting Bracket (sold
separately) is required.
Secure the bracket to the wall with
an ordinary screws and x the device
to the bracket with the supplied
xing screw.
A thread on the base of the device
allows it to be xed to the mounting
plate of a commercial tripod.
When holding the instrument, stretch your arm out and keep it roughly 1.1m from the ground when standing,
or 0.6m when sitting to prevent the moisture and heat generated by your body from interfering with readings.
WBGT-301 WBGT-302
For
▶Work
▶Industrial Hygiene
▶Workplace
Health & Safety
■WBGT instrument x1
■Carrying case x1
■Operation manual x1
■AA size Alkaline batteries x2
Package contents
When holding the WBGT meter Wall-mounted operation Tripod-mounted operation
■Index sticker x1
■Inspection/Certificate x1
■China-RoHS declaration of conformity x1
■Contact information x1
▶Sports
▶Schools
▶Events
▶General Use
For

Model WBGT-301 WBGT-302
Intended use Sports, schools, events etc. For use in the workplace
JIS performance classication Class 1.5*1
IP rating Equivalent to IP65*2 (dust proof and water resistant)
Display 2.8-inch LCD screen (56mm x 42mm)
Measurement capabilities WBGT, ambient temperature, relative humidity, globe temperature
Measurement range
& (display resolution)
WBGT 0.0°C - 50.0°C (displayed to nearest 0.1°C)
Ambient Temperature 0.0°C - 50.0°C (displayed to nearest 0.1°C)
Relative Humidity 10.0% - 90.0%RH (displayed to nearest 0.1%RH)
Globe Temperature 0.0°C - 60.0°C
(displayed to nearest 0.1°C) 0.0°C - 80.0°C (displayed to nearest 0.1°C)
Accuracy
(Under natural draft)
(0.3 to 3 m/sec)
WBGT ± 1.5°C (15°C - 40°C)
Ambient Temperature ± 0.6°C (20°C - 50°C)
Relative Humidity ± 3.0% (30% - 90%RH)
Globe Temperature ± 0.6°C (20°C - 60°C)
Storage temperature Between 0°C and 50°C (indoors)
Storage environment Indoors, free of corrosive and organic gases, low dust,
low uctuations in temperature and humidity
External interface USB Type C
Communication specication*3 USB connection (USB communication/RS communication)
UART connection
Power source Two AA alkaline batteries or USB
Battery life Approximately 6 months*4
Dimensions 69 (W) x 36 (D) x 272 (L) mm
2.7 (W) x 1.4 (D) x 10.7 (L) inches
Weight Approximately 230 g/8.1 oz (battery weight included)
*1 Sensor accuracy is based on the JIS B 7922 stipulation (Japanese Industrial Standards).
*2 Devices conrmed to have IPX5-equivalent water resistance at time of shipment.
Use as recommended in the user manual. Damage due to liquids is not covered by warranty.
*3 Please use the specied cable for connection to the device.
*4 Depending on utilized settings, period of active use, usage environments, etc.
Specifications

2305-52-OM
Optional Accessories & Parts
Wall Mounting Bracket
Used to mount the instrument
on a wall. Includes Fixing Plate &
Fixing Screw 1/4-20UNC.
12-01875 20-12864
USB 2.0 Cable (A to C) 1.0mFixing Screw 1/4 -20U USB 2.0 Cable (A to C) 2.0m
Vent Filter
Carrying Case
Splash-resistant Cover
63-01227
20-13313
64-01783-02
12-08547
Replacement Globe
Performance is adversely
a󱐯ected if the globe is damaged
or dented, so please replace
with this part in such events.
12-08394 12-08395
Replacement Temperature/
Humidity Sensor
In the event that the sensor
malfunctions, breaks or if correct
readings aren't otherwise
obtainable, please replace it with
this part.
Globe Packing
20-13248
Sensor Cap B
20-13246
Removable half of the sensor
housing located at the rear of the
device. Allows access to the
sensor.
Protects the USB port, important
when connected to a cable
outside and in situations with
the risk of splashes. With IPX3-
equivalent water resistance, the
device is adequately protected in
the event of sudden rain.
Used to secure the WBGT Meter
to the Wall Mounting Bracket
(12-01875).
For supplying power and
connecting to a PC.
For protection & safekeeping of
the device and accessories.
Replacement for dirty or lost
Vent Filters.
Packing
20-13243
Protective packing set between
the battery compartment & the
Battery Cover.
Rubber Chip
20-05996
To cover screw recesses and
provide protection.
Battery Cover
20-13256
For replacing a broken or lost
Battery Cover.
Packing gasket for the
Temperature/Humidity Sensor
and Globe. Part 20-13248
includes the packing only.
WBGT-300 series
https://www.kem.kyoto/en/movie/
64-01783-01
For supplying power and
connecting to a PC.
introduction movie
Optional accessories
Spare parts