KEM WBGT-301 User manual

Heat Stroke Checker
WBGT-301 / WBGT-302
Operation Manual
Contents
1. About WBGT-300 series ２
2. For proper usage ３
3. Safety precautions ４
4. Parts configuration and accessories ６
5. Operation buttons ９
6. Measuring method １０
7. How to use １１
8. Measurement １２
9. Display switching １３
10. Date/time １４
11. Change settings １６
12. Memory １９
13. Alarm ２１
14. Other settings ２２
15. Connect to external devices ２３
16. USB communication ２５
17. Replace batteries ２６
18. Storage, maintenance, and handling ２９
19. Part replacement ３２
20. Troubleshooting ３３
21. Optional/Consumable parts ３６
22. Heat stroke index ３７
23. Specifications ３９
24. Warranty and after-sale services ４０
AN 59-00615 Ver.01
Please read this manual thoroughly before using this product for the best
performance of it.
The pictorial illustrations shown in this manual are images.

２
1. About WBGT-300 series
⚫Conform to JIS B 7922:
Electronic Wet-bulb globe temperature (WBGT) index meter
- in conformity with Class 1.5.
⚫Dustproof and waterproof (JIS C 0920):
Equivalent for IP6X of dustproof and IPX5 of waterproof
⚫Memory capabilities:
Up to 30,000 measurement data can be stored on the internal
memory.
Measurement data stored on this product can be transferred to a
personal computer (PC).
⚫USB port:
Measurement data can be summarized and easily transferred to
PC. USB power supply enables continuous measurement for a long
time without worrying about the battery capacity.
⚫Notification with alarm sound
The alarm notifies the danger to the user when WBGT reading
reaches a preset threshold value.
⚫Available for both indoor and outdoor use:
Ordinary thermometer cannot measure the radiation heat, i.e., solar
radiation heat or reflected heat from ground. Thus, under a blazing
sun, correct WBGT (Wet-bulb globe temperature) reading cannot
be determined by it. Whereas this product can be used indoors,
outdoors, or even under a blazing sun because this product is
equipped with a globe so that solar radiation or radiation heat, one
of the causes of heat-stroke occurrence, can be determined.
It may fail to measure correctly if the wind speed is less than 0.3
m/s.
In an enclosed space, such as a closed room, the wind speed will
be less than 0.3 m/s, so the WBGT index will be higher than
indicated by the measuring instrument. Please open the room so
that it can be ventilated.

３
2. For proper usage
⚫Read the indicated value in about twenty (20) seconds when
turning on the unit which keeps lying under outdoor natural draft
for over five minutes.
⚫Wait 1 to 2 minutes until the reading becomes stable even under
outdoor natural draft when this product has just been taken out from
the case or it has been moved to somewhere else. Once the reading
becomes stable, read the indicated value.
⚫Under nearly calm indoor conditions, read the indicated value on this
product after shaking it some five times and waiting for about 10
seconds. Since heat stays in the temperature/humidity sensor under the
environment of strong radiation heat, shake this product well before
measurement in order to replace the air inside the temperature/humidity
sensor with ambient air.
⚫Do NOT leave this product under the environment of strong radiation
heat at 50°C or over. It may cause a malfunction such as the display
disappearing. Shield all parts other than the sensor unit with aluminum
foil or the like when measuring under a strong radiant heat
environment, and expose only the sensor unit.
⚫This product should be placed in the shade when not in use.
⚫If the temperature/humidity sensor unit gets wet, the correct
measurement and display of temperature and humidity may not be
possible until it dries.
⚫Dew condensation may occur due to a sudden change in
temperature and humidity of the environment especially when
taking out this product suddenly from a well air-conditioning room
to places such as high temperature/humidity outdoors. When dew
condensation occurs, the humidity sensor and the built-in circuit
board may be adversely affected. Therefore, please avoid a sudden
temperature change.
⚫Avoid using this product under organic-solvent or hot air
atmosphere to prevent malfunction.
⚫Do NOT use this product under a strong magnetism such as near
a dynamic loudspeaker or a motor.
⚫The temperature/humidity sensor will be gradually degraded
under the influence of the water vapor in the atmosphere.
Therefore, it is recommended that you have an annual inspection
by KEM representative.
Please contact your KEM representative for inspection.

４
3. Safety precautions
Please be sure to follow the safety precautions in order to prevent
harm to users and others and loss of property:
Warning
There may be a risk of death or serious injury if
precautions are not observed.
Caution
There may be a risk of injury or material damage if
precautions are not observed.
Description of prohibited item.
Description of strictly observed item.
Request
Description of keeping this product in the best
conditions.
Notice
Additional information for users in the usage
of this product.
Warning
●This product is not for medical use. The possible heat stroke has
to be cautioned by, other than WBGT index, environmental
conditions, individual difference or physical condition and the wear.
Heat stroke occurs more likely when the person has the experience
of heat stroke in the past or his health condition is not well. An
advanced health check by a medical doctor or at an appropriate
institution is recommended.
Especially, instructors and managers need to be careful when
working in a hot environment.
●Immediately stop using this product if anything abnormal is
found. Clearly mark with “Out of Order”in order to prevent
accidental use by other users, and keep out of reach of them.
Working based on wrong WBGT readings by the faulty meter may
result in death or serious injury in the worst case.

５
Caution
⚫This product is made of precision electronic parts. Do not handle
roughly, not give strong impact, nor dip the temperature/humidity
sensor unit in liquid.
⚫Do not use or store this product in corrosive or organic gas
environment.
⚫Do not damage the temperature/humidity sensor unit, nor immerse
it in liquid. Failure may result in incorrect measurements or
malfunction of this product.
⚫When using a tripod or the like, firmly fix it to something with
sufficient strength. Failure may result in falling of the instrument,
causing an injury and/or the malfunction of this product.
⚫Connect the USB cable 2.0(AtoC) after wiping off any dust or
waterdrops that may have adhered to the USB port of the main
unit. It may cause a malfunction if used with dust or waterdrops
adhered.
⚫Be sure to use this product with batteries in place even when
supplying power from an external source. If the USB cable
2.0(AtoC) is come off while supplying power, the power may
suddenly turn off and it may cause damage of memories.
Notice on this Manual
1. Make sure to read “Safety Precautions” in this manual before
use for safety handling the instrument.
2. Every effort has been made to ensure that information in this
manual is accurate, up-to-date and complete. However, should
you find anything unclear, erroneous description, or any omissions
in this manual, contact your KEM representative.
3. Reproduction, duplication or translation of this manual in whole or
in part is strictly prohibited without permission of KEM.

６
4. Parts configuration and accessories
< Front view >
< Side view >
Globe
< Rear view >
Display
OK button
Control button
Power ON-OFF
button
Temperature/
humidity
sensor
(inside)
USB port
Setting button
< Bottom view >
Sensor cap B
Type
Serial No.
Battery cover
Strap hole for hanging
* Strap is not included
with this product.
Tripod mounting hole
Sensor unit
Clip for battery cover
< View of battery cover removed >
Vent filter
* Be sure not to
block here.
Packing
Setting switch
(under packing)

７
Measurement mode (without sunlight)
Measurement mode (under sunlight)
Minimum value
Maximum value
Temperature display
Globe temperature display
Date/time setting
Memory
Alarm
Contrast
External device connection
External alarm is active：blinking
inactive：lighting
Time display
Icon
Remaining
battery life
< Display >
WBGT reading
Temperature (Ta)/
Globe temperature (Tg)
Relative
humidity (RH)

８
Eco mode
USB communication mode：lighting
RS communication mode：blinking
* Refer to the section ‘Change settings ‘in page 16 for more information
on the displayed icons
* The measured value of WBGT is expressed as WBGT reading in this
manual.
Accessories
WBGT-301／WBGT-302

Operation manual

AA size alkaline battery
Two

Carrying case

Index sticker

Inspection Certificate /Warranty

China-RoHS DECLARATION OF
CONFORMITY(WBGT-301/WBGT-302)

Contact
*In the case that some accessories are short of quantity or damaged, contact
your KEM representative.

９
5. Operation buttons
* Description of buttons:
Power ON-OFF button:
Press and hold this button for more than 3 seconds to turn the
power ON or OFF.
Setting/data transmission button:
Press and hold this button for 2 seconds to proceed to the
parameter settings.
OK button:
Confirm values to be set in the parameter settings.
Up arrow button:
Allows to change parameter values and switch the display of
temperature (Ta) or globe temperature (Tg).
Down arrow button:
Allows to change parameter values and switch the display of
temperature (Ta) or globe temperature (Tg).
Right arrow button:
Allows to change selected items and switch the display of MIN or
MAX.
Left arrow button:
Allows to change selected items and switch the display of MIN or
MAX.

１０
6. Measuring method
About Heat Index (WBGT)
Heat index (WBGT) is the index which focuses on heat balance - the
exchange of heat between human body and outside air. This index
adopts three factors –humidity that has a large effect on the heat
balance of the human body, the surrounding thermal environment such
as sunlight and solar radiation, and temperature - that considerably
affect the heat balance on human body. This index is used to prevent
heat stroke during work or exercises. The calculation of this index is made
with dry-bulb temperature, wet-bulb temperature, and globe
temperature. The unit is [°C].
Under sunlight
0.7 x wet-bulb temperature + 0.2 x globe temperature + 0.1 x dry-bulb
temperature
Without sunlight
0.7 x wet-bulb temperature + 0.3 x globe temperature
This product determines the dry-bulb temperature by temperature sensor,
and the wet-bulb temperature by calculating the relative humidity
measured by humidity sensor and the dry-bulb temperature. The globe
temperature is a value converted from 30mm-diameter globe
temperature to the standard 150mm-diameter globe temperature.
* Refer to page 22 for details on switching of ‘Under sunlight’ and ‘Without
sunlight’.
About the measurement position
WBGT reading should be measured at the height of the human abdomen
area (1.1 m in the standing position, 0.6 m in the sitting position).

１１
Fixing screw
Fixing plate
7. How to use
When measuring WBGT with this product in hand,
try to keep the main unit away from the operator’s
body as far as possible.
* When the operator’s body is so close to the
temperature/humidity sensor unit that the heat of
the body may affect the sensor, resulting in
incorrect readings.
When installing this product on a wall, first secure
the fixing plate on the wall with screws, then, install
this product on the fixing plate with the fixing
screw for mounting a tripod.
* Secure the fixing plate firmly so as not to fall off.
* Screws for mounting the fixing plate are not
included.
When mounting this product on a tripod, secure the
fixing screw for mounting a tripod into the
mounting hole at the bottom of this product.
* Be sure to mount this product with the glove
upwards.
* A tripod and a screw for mounting a tripod are
not included with this product.
Measurement in hand
Measurement by installing on a wall
Measurement by mounting on a tripod
30mm
4 mm *8 mm
Long round hole

１２
8. Measurement
1. Press and hold the power ON-OFF button for more than 3 seconds.
2. Measurement starts immediately after the power is on.
* The screen for Date/time setting is displayed in the initial start-up
time after batteries are first loaded.
A measurement is performed once every 1 second and the display will
be updated.
Press and hold
for more than
3 seconds
Release
button
In initial start-up
time after batteries
are first loaded
In power-on time
when batteries are
already loaded
Power ON screen
Whole screen lighting
Date/time setting:
* For details of Date/time setting, refer to Page 14.
Measurement screen
After completing the
setting

１３
9. Display switching
This function can be used on the measurement screen.
1. Press up/down arrow button to switch the display of temperature
(Ta) or globe temperature (Tg).
2. Press left/right arrow button to switch the measured value of
minimum (MIN) or maximum (MAX).
* Possible to switch the screen with either Up or Down arrow button.
* Possible to switch the screen with either Right or Left arrow button.
Switching temperature (Ta) or globe temperature (Tg)
Switching minimum value (MIN) or maximum value (MAX)
Measurement screen (Ta)
Measurement screen (Tg)
Measurement screen (MIN)
Measurement screen (MAX)
Measurement screen

１４
10. Date/time
1. Put the batteries in, then press and hold the power ON-OFF button for
more than 3 seconds.
2. When the power is turned on for the first time after replacing the battery,
the screen for setting Date/time will be displayed first after startup. The
setting method is described below.
(Example) When setting July 9, 2023:
[Set year]
Move the digit to be selected Set the value to ‘23’ and go to month setting
[Set month]
Move the digit to be selected Set the value to ‘07’ and go to day setting
[Set day]
Move the digit to be selected Set the value to ‘09’ and go to hour/minute setting
Set date

１５
(Example) When setting to 13:48: (24-hour clock)
[Set hour/minute]
Notice
Date/time setting need to be set the first time the battery is loaded
and the power is turned on. It can be changed later.
In this case, after changing the settings, press “OK”button to
return to the setting change screen.
Set time
Set the value to ‘1’
Move the digit to be selected
Set the value to ‘3’
Move the digit to be selected
Set the value to ‘4’
Move the digit to be selected
Set the value to ‘8’ to complete the settings
Press “OK” button to return to the measurement screen

１６
11. Change settings
This product features the following setting items.
The contents of setting items are displayed with icons shown as
below.:
Item
Icon
Content
Date/time
Set date and time
Memory
Set memory function for stored data
(Also used in connecting with an LED
indicator.
Alarm
Set a temperature when the alarm
sounds.
Contrast
Set contrast of screen display
Connection to external device
Set connection with a rotating red light.
Only for UART connection
eco mode
Set auto power-off
Switch measurement mode
Switch measurement mode
(Under sunlight)
Switch measurement mode
(Without sunlight)
USB communication
Switch USB connection method
When changing the settings, press and hold button for 2
seconds. Further, when returning to the measurement screen
from the screen of changing settings, press button. Pressing
button while an icon is blinking will make transition to the
advanced settings screen of the item. When the settings of an
item are completed, the screen will return to that of changing
settings.
For the information on button controlling or scrolling, refer to
page 17.
* For setting the date and time, please refer to "Set date" on page 14.
* Refer to page 19-25 for more details on other setting.

１７
Select an item to be set.
* When returning to the measurement screen, press button.
How to select setting items
Parameter setting screen
Move the icon to be selected (to the right)
Long press
Move the icon to be selected (to the right)
Move the icon to be selected (to the right)
Move the icon to be selected (to the right)
Move the icon to be selected (to the lower)
Move selection icon (to the right)
Move the icon to be selected (to the right)
Move the icon to be selected (to the upper)
Press ‘OK’ button to proceed to the advanced settings
Press twice

１８
Switch the setting switch to change the connection mode depending
on the device to be connected to this product.
USB connection：Use it to connect to your computer. Please prepare
a USB2.0 cable (A to C).*1
UART connection：Use this cable to connect to peripheral devices
such as PATLITE and LED indicators.
*1. Please refer to page 36 for purchasing information.
Connected
device
Connection
mode
Setting switch
1
2
PC
USB
connection
OFF
OFF
Peripherals
UART
connection
ON
OFF
* Refer to page 23, 25 for more details of the setting.
The setting switch is in the battery box of the main unit.
(Default : USB connection mode.)
When switching the setting switch, turn off the power and remove
the batteries. A tip of a precision screwdriver or similar tool should be
used for switching.
Wait at least 15 seconds before installing the batteries, as the inside
batteries need to be discharged to switch the settings using the
setting switch.
Setting up connections to peripheral devices
ON
OFF

１９
12. Memory
The memory function features recording measurement data.
Up to 30,000 measurement data can be stored in the memory.
The settable memory interval is from 1 min to 999 min.
(Default: OFF)
Select the memory icon from the screen of changing settings.
Recording interval in memory
* Data can be stored at the preset memory interval even if the power
is turned off.
Select ON/OFF
When ‘ON’ is selected, go to interval in memory setting.
Proceed to the selecting digit and set the recording interval in the memory.
Press “OK” button to complete the setting and start recording the
measurement data.
(When set to OFF in the ON/OFF selection, recording is stopped.)

２０
Notice
About the contents of the memory of the WBGT main unit
Csv files will be created in the WBGT folder.
File name: WBGT_ Serial No._Date of file creation
Example: WBGT_32602009_210716
5,000 data will be stored in one csv file.
In addition, the following items will be recorded for each case.
Measurement date and time/measurement mode (without sunlight : 0, under
sunlight: 1) /WBGT/Ta/RH/Tg
The oldest file (batch of 5,000 data) will be deleted when the number of files
exceeds 7 (35,000 data). Therefore transfer the data in an appropriate time.
The stored data can be checked and transferred by connecting the unit to a
PC. Please set the communication mode to USB communication mode.
Refer to page 18, 25 for more details of the setting.
Be sure to turn OFF the memory function before removing
batteries. Otherwise (remove them when the function is ON), the
measurement data file can be damaged
When the remaining battery level becomes lower, the memory
function will not work. Therefore, periodically replace butteries.
The memory icon blinks when the available data storage capacity
is low. Be sure to transfer or delete data as early as possible.
When the memory function is turned on, the eco mode is forced
to turn off.