Bosean Electronic Technology BH-4M User manual

BH-4M
Portable Multi-gas Detector
User Manual
Bosean Electronic Technology Co.,Ltd
ISO9001-2015

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1. Brief Introduction
BH-4M portable gas detector (hereinafter referred to as the
detector) is an intelligent multi-parameter detector designed with
advanced integrated circuit technology, standard design
technology and proprietary digital-analog hybrid communication
technology.
The detector adopts natural diffusion or pump suction sampling
method for gas sampling, and the sensitive element adopts
high-quality gas sensor for gas detection. It has good sensitivity
and excellent repeatability. It is easy to use and maintain, which
greatly meets the safety detection of industrial sites. For the
requirements of high reliability of the equipment, the shell is made
of high-precision engineering plastics and non-slip rubber, with
high strength and good hand feeling. It can be widely used in
petroleum, chemical, environmental protection, smelting, refining,
biochemical medicine, agriculture, science and technology,
universities and other industries and fields.
The detector can detect 1-4 gas combinations according to
customer needs. Using integrated modules, it integrates
electrochemistry, catalysis, semiconductor, thermal conductivity,
optics and other detection principles to provide users with reliable,
accurate and safe gas detection solutions.
2.Instrument features
2.1 Features
* The new GUI design scheme is adopted, the interface display is
more comprehensive, and the operation is more user-friendly.
* Natural diffusion or pumping gas detection methods can be

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selected, and 1 to 4 gas types can be detected at the same time.
* Using miniature vacuum sampling pump, stable flow, long life
and low noise.
* It adopts a 2.0-inch high-definition color screen with a wide
viewing angle of 120 degrees.
* The three-button operation is simple and intuitive.
* Support a variety of extended functions to meet users' different
product applications.
2.2 Functions
*Sound, light, vibration and display four alarm modes.
*It supports switching between real-time gas concentration data
display and real-time curve display mode.
*It supports multi-point calibration, up to 5 points calibration.
*Multiple data storage methods, alarm storage, manual storage.
*Support Chinese and English switching, other languages can be
customized.
*Large-capacity (2500mAh) rechargeable lithium battery, which
can last longer.
*The USB interface adopts Type-C interface, and there is no fear
of plugging in front and back.
*Support TWA, STEL alarm function.

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3. Technical Data
Target Gas
Range
Low alarm
High alarm
Resolution
CH4
0～100%LEL
20%LEL
50%LEL
1%LEL
H2S
0～100ppm
10ppm
35ppm
1ppm
CO
0～1000ppm
50ppm
150ppm
1ppm
O2
0～30%vol
19.5%vol
23.5%vol
0.1%vol
Other gases needed, please contact supplier
Gas sampling method: Pump suction type, natural diffusion type
Response time: Pump suction type T90＜30s, natural
diffusion type T90＜60s
Detecting gas: Support 1~4 kinds of gas detection
Accuracy: ≤±5% F.S.
Indication: 2.0 inch color display, resolution 320*240
Alarm methods: Acousto-optic vibrating display quadruple
alarm, TWA/STEL alarm
Data communication: Support USB to connect to the upper
computer of the computer to view data
System language: Support Chinese and English switching;
other languages can be customized
Working environment: Temperature -10℃~50℃;
humidity<95%RH (no condensation)
Power Source: DC3.7V (Lithium battery capacity
2500mAh)
Charging way: Type-C charging interface, 5V/1A standard
charger
Standby time: ≥8h
Charging time: <5h
Gas Sensor Life: 2 years
Protection Grade: IP65
Weight: 372.5g(include pump)
Dimensions: Pump suction type 160*69*75mm; natural
diffusion type 150*69*55mm

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4. Structure
4.1 Structure function comparison table
4.1 Detector structure
It is mainly composed of shell, circuit board, battery, display screen,
sensor, charger and other components.
4.2 Sensor working principle
Electrochemical and catalytic combustion.
5. Function and operation
5.1 Power-on self-test and warm-up
When the detector is turned off, press and hold the middle button
for 3 seconds, the display of the detector displays the welcome

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interface (as shown in Figure 1), and then the instrument performs
the system initialization operation, and then performs the system
self-check and pre-check (sound, light, vibration, channel, etc.)
heat. When the preheating is completed, enter the main detection
interface of the detector (Figure 2).
Figure 1 Figure 2
5.2 Turn off
In the main menu interface of the detector, press and hold the
middle button for 3 seconds and then release the button to enter
the shutdown operation interface (Figure 3), click the left "Yes" to
confirm the shutdown, and click the right button "No" to cancel the
shutdown. Press and hold the middle button for 5 seconds to shut
down directly.
Figure 3

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5.3.1 Main interface function description
a. Display the current date and time.
b. Pump status indication. When the pump is normally turned on,
the icon rotates and the color changes to green; when the air
pump is normally closed, the icon does not rotate, and the color
changes to gray.
c. Buzzer status indication. When the gas concentration detection
is in the normal state, the icon is green; when the gas
concentration detection is in the low or high alarm state, after
pressing "Mute", the icon turns red.
d. Battery level indicator. The battery level is divided into six bars.
When there are two bars remaining, the icon turns yellow and the
screen prompts that the battery level is low. When there is one bar
of power remaining, the icon turns red and the screen prompts that
the battery power is low. When the power is exhausted, it will
automatically shut down.
5.3.2 Main interface display description
The detector shows the real-time
concentration of the relevant gas in the
environment as shown in Figure 4 under
the normal detection state.
Figure 4

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When the gas concentration detected by the detector is lower than
the set alarm value (Note: when the oxygen concentration is
higher than the low alarm value and lower than the high alarm
value), the detection status bar only displays the concentration
Value, no abnormal display.
When the gas concentration detected by the detector is higher
than the set low alarm value (Note: when the oxygen
concentration is lower than the set low alarm value), the detector is
in the low alarm state, the gas concentration value display color
changes to red, and the status bar displays "L", and the buzzer
beeps at 0.5s intervals, the alarm lights on both sides of the
screen flash synchronously, and the vibrator vibrates. If the screen
is in the off state, the screen lights up at the same time.
When the detector detects that the gas concentration is higher
than the set high alarm value, the detector is in the high alarm
state, the gas concentration value display color changes to red,
the detection status bar displays "H", and the buzzer emits "di" at
an interval of 0.25s. The beep sounds, the alarm lights on both
sides of the screen flash simultaneously, and the vibrator vibrates.
When the detector detects that the gas concentration is higher
than the sensor range, the detector is in the over-limit state, the
gas concentration value is displayed as red "HHHH", the detection
status bar displays "OV", and the buzzer interval 0.25s sends out a
"di" beep, the alarm lights on both sides of the screen flash
simultaneously, and the vibrator vibrates.

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When the detector detects the gas concentration for 8 hours, when
the calculated TWA value exceeds the set value, the gas
concentration value display color changes to red, and the
detection status bar displays "T".
When the detector detects the gas concentration for 15 minutes,
when the calculated STEL value exceeds the set value, the gas
concentration value display color changes to red, and the
detection status bar displays "S".
Note: When the alarm mute function is turned on, if a new alarm
state occurs, the buzzer will resume ringing.
When the gas concentration detected by the detector returns to
the lower limit alarm value, the gas concentration value color will
change to green, and the alarm signal will be automatically
released at the same time.
When multiple alarm states are detected in the same gas channel,
only the highest priority alarm will be issued.
The police priority is as follows:
Normal <Low alarm <High alarm<TWA <STEL <Out of limit
5.3.3 The main interface button function
description
Click the left button in the main interface to enter
the "Record" interface (Figure 5). Right-click to
select the gas to be viewed, and after clicking the
middle button, the gas alarm record operation can Figure 5

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be viewed on the interface (Figure 6). Single-click the right button
to turn the "next page" page, click the left button to turn the
"previous page" page, click the middle button to return to the
Figure 5 interface, and click the left button to return to the main
interface.
Right-click in the main interface to enter the "curve display"
interface (Figure 7). In this interface, you can view the real-time
detection curve of a certain gas channel within 10s. Click the left or
right button to switch the channel display, and click the middle
button to return to the main interface.
Click the middle button in the main interface to enter the "Main
Menu" interface (Figure 8). Click the left and right buttons to select
the function icon. Click the middle button to enter the
corresponding function interface.
Figure 6 Figure 7 Figure 8
5.4 Navigation bar function description
The navigation bar is displayed in three grids, corresponding to
three buttons respectively, and the corresponding functions can be
realized by operating the buttons.