Dahua Technology BF 5421 User manual

Thermal Camera Installation Guide
(BF 5421)
V1.7
Zhejiang Dahua Technology Co., Ltd

Preface
Summary
The temperature of all materials is higher than absolute zero (- 273.15 ℃) and radiates
electromagnetic wave continuously. The thermal imaging camera collects the infrared radiation
energy emitted by the measured objects, and establishes the accurate corresponding relationship
between the target energy and temperature through complex temperature measurement
algorithm and blackbody temperature measurement calibration and other processes, so as to
realize the temperature measurement function of human body. It is characterized by non-contact,
multi-objective, fast, and no risk to the temperature measurer. It can be easily deployed in densely
populated public places, and it can effectively and safely screen the abnormal temperature
preliminarily.
Thermal imaging human body temperature measurement, mainly through the measurement
of human forehead and face temperature (according to the different environment of about 31-
36 ℃), preliminary judgment, found that the suspected abnormal temperature, and then use ear
temperature gun or mercury thermometer to further confirm. As the skin surface of forehead and
face is exposed to the air, the temperature changes due to the influence of air flow and sweat.
Generally, under the indoor ambient temperature of 15 ℃in winter, if the forehead temperature
exceeds 35 ℃, there is a possibility of fever. For other environmental temperature conditions, it is
recommended to measure several samples on site, and increase 1 ℃as the alarm threshold on
the basis of normal forehead temperature.
The human body temperature measurement requires high precision, which requires high
installation mode, environment and debugging. Please read this article carefully.
Combined with the support experience of the thermal imaging R & D technical support
team, this manual describes the installation requirements, common operations and precautions
during the actual use of thermal imaging products, so as to facilitate the quick start and reduce
unnecessary problems. For more detailed instructions, please refer to the product manual and quick
operation manual.
The content described in this article needs to be analyzed in combination with the actual field
equipment, which is not the only way. If you have any questions or good suggestions, please
contact Xu Fangrong (Short NO: 693802), Fang Lu (Short NO: 685718), Li Fuxiang (Short NO:
638137), Fang Shengdong (short: 669126).
⚫This manual is only for internal use of Dahua employees. Please do not directly provide
it to customers or publish it to public platforms such as the Internet.
⚫Reading objects include (but not limited to): Solution Engineer, Pre-sale / in-sale / after-sale
technical support engineer, installation and debugging personnel, product engineer, test
engineer, marketing and sales personnel and other internal personnel of the company

Change Record
Revision date
Version number
Creater
Reviser
2020.01.27
V1.0
房圣东
2020.01.28
V1.1
许芳荣/房圣东
房圣东
2020.01.31
V1.2
房圣东
李静
2020.02.03
V1.3
方璐
房圣东
2020.03.14
V1.7
方璐
房圣东

Content
Preface ...............................................................................................................................................................................I
1Equipment Installation...........................................................................................................................................2
1.1 Installation Preparation .................................................................................................................................................2
1.2 Installation Distance........................................................................................................................................................ 2
1.3 Installation Diagram .......................................................................................................................................................3
1.4 Real Scene Diagram .......................................................................................................................................................3
1.5 Installation Precautions .................................................................................................................................................5
2General Settings.......................................................................................................................................................7
2.1 Equipment Upgrade....................................................................................................................................................... 7
2.2 Debugging Of Human Body Temperature Detection Function ......................................................................8
2.2.1 Selection of human body temperature measurement intelligent scheme...................................... 8
2.2.2 Blackbody Parameter Setting..........................................................................................................................8
2.2.3 Drawing Of Human Body Temperature Detection Area......................................................................10
2.2.4 Alarm Temperature Correction.................................................................................................................13
2.2.5 Binocular target setting and fine adjustment function.........................................................................13
2.2.6 Opening / closing function of visible light face thermometer...........................................................14
3 Announcements ................................................................................................................................................... 15
4 FAQ.............................................................................................................................................................................. 16

1Equipment Installation
1.1 Installation Preparation
⚫Installation Preparation：
◼5 meter long tape for distance measurement on site
◼DC12V adapter, used with camera
◼Some cable lines
⚫Product appearance
BF5421：Blackbody：
Note: the recorded installation guidance video "Dahua indoor human body
temperature measurement product installation video (BF3221)", which adopts
tripod mode, is applicable to portable indoor installation guidance reference,
and other fixed installation needs to be installed in strict accordance with the
specified height, distance and other requirements.
The PPT version of installation guidance video, web operation guidance
and guidance document should be obtained from the regional delivery
supervisor. In the future, it will be synchronized in the group on the mobile app.
1.2 Installation Distance
focal length
Distance between
blackbody and
camera
Distance between
human forehead and
camera
Width at the best
distance of
temperature
measurement
BF5421
（13mm）
3m
3m
(NO Blackbody2m)
1.5m
The distance from the forehead to the camera and the distance from the blackbody to
the camera have the best temperature measurement accuracy. Taking BF542121

(13mm) as an example, the distance between blackbody and camera is 3M, the best
distance for temperature measurement is 3M (the straight-line distance between the
front of forehead and camera), the best test width at 3m is about 1.3m (about one
gate), the forward temperature at 3m will be higher, and the backward temperature
will be lower. The ideal situation is to place footprints at the 3m position to guide the
thermometer to measure temperature one by one at the designated position.
1.3 Installation Diagram
⚫BF5421(13mm) installation diagram
1.4 Real Scene Diagram
⚫BF5421(13mm) as an example
Blackbody
Height 1.8m
Thermal Camera
Height 2m

Sticking foot stickers at the temperature measurement position
⚫Monitoring picture, the following is the effect of one person in front of the 13mm
lens at the 3m position
1.5 Installation Precautions
⚫The thermal imaging camera and blackbody are installed on the same side to
avoid the occlusion between the camera and blackbody ，the blackbody
radiation surface should be facing the camera. If the blackbody is facing the
camera, the four sides of the blackbody shell will not be exposed, as shown in
the following figure:
⚫The moving direction of the flow of people is toward the camera. During the
test, the forehead of the target person is facing the camera. It is better to stay
and face the camera for temperature measurement. Temporary measures can
be adopted on site to plan the walking route of personnel and guide the person
to the camera position; for scenes with large indoor and outdoor temperature

difference, multiple bow type routes can be planned and the area with wind at
the door shall be avoided, and the temperature measurement can be
conducted after the person reaches the indoor forehead temperature to be
stable.
⚫The black body radiation surface (Note: the radiation surface shall not be
touched or dirty) shall be facing the camera irradiation direction, the black body
shall be on the left or right side of the thermal imaging picture, and the tripod
can be protected by temporary fence.
As follows, we divide the picture into 16 equal parts, the best position of the
blackbody: put it on the top left or top right in the middle position of the ‘Cross
type’:
⚫It is required that the visible light channel has enough illumination and avoid the
influence of backlight / reflection / change of strong light / occlusion, etc.
⚫It is forbidden to have high-temperature heat source or sunlight in the thermal
imaging picture, to avoid the interference of heat source such as heater, hot water
point, microwave oven, high-power lamp, radiator, etc., so as to avoid the damage
of detector.
⚫The installation area shall be relatively isolated from the outside environment
without wind and stability, to avoid the outdoor or the scene connected with the
outside, which is not suitable for the environment with air flow or strong
electromagnetic interference or vibration.

Installation scenarios to avoid
Insufficient light.
Backlight / scene open
to the outside
The direction of people moving is not toward
the camera.
2General Settings
2.1 Equipment Upgrade
The new factory version of the program already supports human body temperature
detection and does not need to be upgraded. If there is a new iterative process will be
notified in the delivery group, please pay attention to the group information in time.
Note:
(1) After 20200210, the black regular box of the program is rectangle.
(2) Programs prior to 20200228 need to be upgraded to the latest, first upgrade the main
program, and then upgrade the thermal imaging core program. After the upgrade, restore
the default and clear the browser cache.
(3) When operating "restore factory settings", "program upgrade", "clear configuration",
"power off and restart", "soft restart", power off is prohibited before the completion of
equipment startup. Important signs of the completion of device startup: Ping connected,
web login.