MEWOI WBGT2019A User manual

WBGT Heat Stress Monitor
WBGT2019A, WBGT2019B
User Manual
www.mewoi.com

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Contents
Chapter I Introduction
Section I Background ···································································3
Section II Instrument information ····················································3
Chapter II Functions
Section I Overview ·····································································7
Section II Specification ································································7
Section III Data processing ···························································8
Chapter III Measurement Operation
Section I Measurement preparation ··················································8
Section II Basic operation ······························································10
Section III Measurement application ················································12
Chapter IV PC Software
Section I Overview ·····································································25
Section II Operation ····································································28
Chapter V Maintenance of Instrument
Section I Calibration ···································································33
Section II Storage········································································34
Appendix I：ACGIH Clothing Corrections ······································34

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Chapter I Introduction
Section I Background
The WBGT2019A model, used for monitoring traditional heat stress index, is
portable and easy to use. It can accurately and rapidly measure the relative indexes
of the heat stress intensity of the individual under specific thermal environment.
WBGT2019A can measure dry-bulb temperature, wet-bulb temperature, black
globe temperature and relative humidity simultaneously,and calculate indoor and
outdoor WBGT, H.I and HU indexes. In addition, it can evaluate stay time
according to ACGIH TLV manual to determine the working time and stay time of
the staff in the working environment. It can communicate and export data with the
PC through USB. The attached PC software can be used for data analysis and
processing.
Section II Instrument information
WBGT2019A is applied to the workplace with high temperature. The main
monitoring indexes are WBGTi, WBGTo and humidity.
Accessories and usage
Items
Quantity
Functions
Pictures
Note
Master-
Device
1
Data logging
and
processing.
Sensor
1
Measuring of
physical
parameter.
Sensor set.
Power
adapter
1
DC9V, 1A,
used for the
external
powering of
master-device.
Four different model
adapters, in line with
the European
standard, American
standard, British
standard.

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Commu
nication
Cable
1
Data
transmission
cable.
Wrist
strap
1
Detachable,
fall-prevention
For master-device.
Packing
bag
1
Nylon
material
portable bag,
Eco-Friendly
material inner
filler.
PC
softwar
e
1
For data
import and
post-processin
g.
Flash disk.
Manual
1
User manual
Paper documents.
Stand
1
Tripod.
Optional accessories
Tri-sens
or stand
1
For tri-sensor
measurement.
Optional accessories
Calibrat
ion
report
1
Test report of
the instrument
before
delivery.
Paper documents.
Packing
list
1
Package
contents
Paper documents.

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Technical parameters
Parameters
WBGT2019A
Note
Measurement index
Dry-bulb
temperature
range
0—85°C
Dry-bulb
temperature
accuracy
±0.5°C (full range)
Wet-bulb
temperature
range
0—85°C
Wet-bulb
temperature
accuracy
±0.5°C (full range)
Black globe
temperature
range
0—85°C
Black globe
temperature
accuracy
±0.5°C (full range)
Black globe
diameter
50mm
Humidity range
0—100%
Relative Humidity
Humidity
accuracy
±3%
Power supply
Built-in power
supply
Four AA batteries
Non-rechargeable
battery

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Endurance
Not less than 48 hours
External power
supply
DC9V，1A
Dedicated adapter
Data logging and display
Sensor
channel
3 channels
Screen
Monochrome LCD
Viewing area ：
60*42 mm
Language
English
Portuguese
Recording
interval
1-60 minutes (set arbitrarily)
10 minutes by
default
Data output
USB port.
Export the data stored in master-device
to PC.
Appearance and material
Instrument
material
Flame-retardant ABS & rubber
Dimensions
280*220*60 mm
Packaging form
Nylon material portable bag,
Eco-Friendly material inner filler
Package size
460*390*140 mm
Structural type
Separation design of sensor and
master-device
Accessories
Data cable
Micro USB
Operating environment and IP code
Temperature
5—60°C
IP Code
IP54

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Chapter II Functions
Section I Overview
I Basic function
WBGT2019A model is mainly used to measure the environmental
parameters of dry-bulb temperature, wet-bulb temperature, black globe
temperature, and calculate the WBGT heat index.
This series of instruments can carry out field evaluation of the environment
to be measured according to the standard while measuring main heat
environment parameters. The main evaluation results include the stay time under
different work intensity.
Section II Specification
I Instrument composition
WBGT2019A is composed of sensor, master-device and other parts, as
shown in Figure 1 and Figure 2.
Figure 1 Front view of WBGT2019A
①Wet-bulb temperature sensor②Dry-bulb temperature and humidity sensor
③Sensor locking screw ④Black globe temperature sensor
⑤Sensor seat ⑥Wrist strap ⑦Master-device ⑧Communications indicator
light ⑨LCD screen ⑩Keyboard
①②③④
⑤
⑥⑦
⑧
⑨⑩

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Figure 2 Rear view of WBGT2019A
①Battery cover ②Sensor indicator light ③Power button ④USB port
⑤CH1 interface ⑥CH2 interface ⑦CH3 interface⑧RS485 interface
⑨External power supply interface
Section III Data processing
The evaluation algorithm of relevant standards is built into the
WBGT2019A, which can directly conduct field evaluation and give evaluation
results. The data can also be shown as curve. At the same time, data can be
uploaded to the PC to conduct data processing through PC software.
The master-device can record the data automatically after setting the record
interval. Refer to the operation instructions and the software section for more
details.
Chapter III Measurement Operation
Section I Measurement preparation
I Power supply
There are two options for powering WBGT2019A: four standard AA
batteries, and external DC9V power.
①②
③
④
⑤⑥⑦⑧⑨

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To install AA battery, remove four fastening screws with a screwdriver and
install the battery with correct polarity (note the battery polarity marked in the
unit), and then tighten the cover plate with screws (be sure to tighten it, the
instrument is waterproof in design, the battery box has waterproof function). See
the orange box of Figure 3.
Figure 3 Battery and external power supply
External power supply adopts the DC9V power adapter which is equipped
with a specific interface to attach the instrument. Plug the connector into the
interface on the right of back. See the orange circle in Figure 3.
II Equipment arrangement
WBGT2019A is a portable instrument, there is a 1/4 inch screw hole on the
bottom of the master-device, a standard tripod can be connected. See Figure 4.
Note: on the battery cover a label of important information of this instrument is attached. When replace the
batteries of several instruments at the same time, please be sure to install them correspondingly.
There is corresponding instrument number inside the battery box, which is the same as the number on the battery
cover to avoid misplacing.
The power adapter is equipped with a variety of replaceable plugs, which can adapt to the standards of the United
States, the United Kingdom, Europe and other regions.

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Figure 4 1/4 inch screw thread
Section II Basic operations
I Sensor preparation
The sensor of WBGT2019A and the master-device are designed for split use.
The default state is: the sensor is fixed on the top of master-device by
self-contained locking screws, as shown in Figure 5. During assembly, the 9-pin
plug shall be inserted and the two lock nuts shall be tightened in place, otherwise
there may be poor contact.
Insert the cotton belt onto the metal rod of the wet bulb sensor from the
middle of cotton belt, the lower end of the cotton belt should be at the bottom of
the cup. Fill pure water to the cup of wet bulb sensor, till the cotton belt is all
soaked. Pour the remaining water from the wet-bulb sensor cup after test.
Figure 5 DB9 plug on the bottom of sensor
II. Key function
WBGT2019A is equipped with waterproof membrane keyboard. Some keys
have multiple functions, for example，SET key also can be used to shift the
cursors. The specific form is shown in the following table:
Note: Tripod is highly recommended while field testing.

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III. On/Off
Power button of WBGT2019A is a silicone waterproof button. After
pressing the button, the power will be turned on, the indicator light on the
membrane keyboard will be on, and the screen will display boot screen. By
pressing the button again, the indicator light will go out and the power will be cut
off. See Figure 6.
Figure 6 Power button
Set key
Enter setup menu
Up key
Circularly increase number
or shift upwards
Down key
Circularly reduce number
or shift downwards
OK key
Confirm settings
Return key
Return to previous menu
Note: WBGT2019A has the sleep function, under sleeping state, the LCD will be shut off.
Please observe the indicator light to see if the power is off instead of the display state of LCD.

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Section III Measurement application
I Usage mode
Portable mode: WBGT2019A can be used in a variety of ways. The default
mode is portable mode in which single master-device and single sensor is
connected. The master-device and single sensor are fastened by the
self-contained screw of sensor. See Figure 7.
Figure 7 Portable mode
Separation mode: Connect the master device and the sensor by a special
extension cable. The 5-core aviation connector on the cable is plugged into CH1
on the master-device, plug the 9-pin DB9 connector to the bottom interface on
the sensor, then tighten the screws. By default, the first channel of CH1 is
connected with the standard sensor. See Figure 8.
Figure 8 Separation mode

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II Tri-sensor measurement mode
WBGT2019A can achieve multi-channel measurement by a single
master-device and three sensors. Follow the steps below:
Step1: The three sensors are connected to the three channels of CH1, CH2
and CH3 respectively with special extension cable according to instrument
number.
Step2: Cover the DB9 socket on the top of the master-device with a
waterproof cap to prevent accidental water inflow on site.
Step3: Three sets of sensor can be fixed with tri-sensor stand, and different
heights can be set. See Figure 9.
Figure 9 Tri-sensor mode
III Operation interface
1. ON/OFF
Press power bottom to turn on and off the WBGT2019A. A boot screen will
be shown after power on. User can press or key to select function at
root menu, press key to enter parameter setting menu directly. If there’s no
any key operation after turn on the power in a few seconds(less than 5s), the
screen will jump to Continuous measurement directly.

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2. Function selection
Press and key to select the function menu, and then press
to enter the corresponding interface; Press key to enter the parameter
setting interface directly. See Figure 10.
Figure 10 Function selection interface
3. Continuous measurement
After power on, if there is no key operation for 5 seconds, the master device
will automatically start continuous measurement. Continuous measurement has
five interfaces when one sensor connected, if three sensors connected, there will
be seven interfaces. Within 15 seconds, master device will detect the numbers of
connected sensors and adjust interface quantity automatically.
After entering continuous measurement, the values of CH1 will be shown in
the first interfaces, press or key to jump to other interfaces. In other
interfaces, press the key to return to the first interfaces of continuous
measurement. While three sensors connected, there are three interfaces will
correspond to the values of CH1, CH2, CH3 sensors. When the other two sensors
are not connected, the corresponding measurement interface will not be shown.
The second interface is the measurement interface for tri-sensor, which is used to
calculate the real-time average value of WBGTi. When the CH2 and CH3 are not

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connected, the second interface which is WBGT(W) calculation interface will not
be shown. In the third interface, real time TLV value accroding to ACGIH will be
shown, WBGTi and WBGTo will display them by cyclic switching at 10s
intervals. As shown in Figure 11.
Figure 11 Continuous measurement interfaces
The fourth interface shows the real time value of Td (dew point
temperature), HI (heat index), HU (humidity index) are the average of the current
data from the beginning of storage (calculated from the occurrence of latest
“ ” mark). The fifth interface is the trend curve interface, and only used to
generate the curve of WBGTi. From about 20 minutes before the present time,
record a data every 10s. As shown in Figure 12.
Figure 12 Continuous measurement interfaces
In all interfaces, press key to start data recording, and there will be a

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recording mark in the lower right corner, the number on the right means
recording interval; press key again, recording will stop, and there will be a
recording mark in the lower right corner.
4. Discontinuous measurement
After selecting the interface to enter the discontinuous measurement, the
timing setting interface will be shown first, and three periods of time for
measurement will be shown at the same time, as shown in Figure 13. User can
modify the three periods of time, if there is no key operation for 10 seconds, the
interface will switch to the measurement interface automatically, and conduct
measurement according to the default period. Discontinuous measurement has
six interfaces when one sensor connected, if three sensors connected, there will
be eight interfaces. Within 15 seconds, master-device will detect the numbers of
connected sensors and adjust interface quantity automatically.
Figure 13 Timing Setting interface
The first interface is real-time measurement. Press key in other
interfaces will return to timing setting interfaces. The first three interfaces are
corresponding to the values of CH1, CH2, CH3 sensors, values of the sensors
that have been connected are displayed only. Instrument will run at the specified
time and automatically record the data. The second interface is the tri-sensor

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measurement interface, which is used to calculate the real-time average value of
WBGTi. When CH2 and CH3 are not connected, the second interface which is
WBGT(W) calculation interface will not be shown.
In the third interface, real time TLV value accroding to ACGIH will be
shown, and WBGTi and WBGTo will be displayed by cyclic switching at 10s
intervals. The standard mode is shown in Figure 14.
Figure 14 Discontinuous measurement interfaces
The fourth interface displays the real time value of Td (dew point
temperature), HI (heat index), HU (humidity index) are the average stored from
the beginning. The fifth interface is the trend curve interface, and only used to
generate the curve of WBGTi. From about 20 minutes before the present, record
a data every 10s. As shown in Figure 15.

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Figure 15 Discontinuous measurement interfaces
Key assignments: Press key in timing setting interface to move cursor,
press and keys to modify timing values. After setting the timing time,
there are two ways to enter the measurement interface: one is to press after
the cursor is moved to “start-up”; the other is to automatically jump to the
measurement interface without any key operation for 10 seconds. Press and
keys to switch interface (measurement interfaces only), press the key
to return to timing interface, press the keys at measurement interfaces to
return to the timing interface. Press the key under timing interface will
return to the function selection interface. Press key under any interface to
return to setup interface directly.
In all interfaces ,press key to start data recording, and there will be a
recording mark in the lower right corner, the number on the right means
recording interval; press key again, recording will stop, and there will be a
recording mark in the lower right corner.
5. Calibration
Press key to return to the function selection, press the and
keys to move the cursor to the “Calibration” icon, press to enter the
“Calibration” main interface (select the channel).
There are two calibration modes: “Administrators” (factory calibration

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mode) and “User” (User calibration mode). User can click “User” to enter
channel selection interface, moves the cursor to select the channel by pressing
the and keys, and press to enter the corresponding calibration
interface. In the calibration interface, press key to move the cursor, and
press and keys to modify value, then press the key for
calibration, and the “Calibration?” will be displayed. Press “Calibration
finished” will be displayed at the bottom of the interface, and press key to
cancel the calibration. During calibration, items shall be calibrated separately.
After calibration, press key to return to channel selection interface, and
press the key at channel selection interface to return to the function
selection interface at the channel selection interface. See Figure 16.
Figure 16 Calibration interface
6. Parameter setting
User can enter parameter setting interface by two ways: one is by pressing
key directly while measuring; the other is by pressing the and
keys to move the cursor to the “PAR-SET” icon in the function selection
interface, then press to enter the parameter setting interface.
In the parameter setting interface, press the and keys to select
the items that need to be set, and then press to enter the items that need to
be modified, as shown in Figure 17