Hehua brand capacitive target flowmete

  Basic structure and working principle of Hehua hHB series capacitive target flowmeter
1
Structure
  Hehua hHB capacitive target flowmeter is mainly composed of measuring tube (shell), new capacitive force sensor (including flow blocking element), integration display and output
According to different media and working conditions, appropriate capacitive force sensors are selected
Therefore, the user provides accurate measurement objects and parameters, and the manufacturer selects appropriate capacitive force sensors is the key to the accuracy of product measurement
working principle
  When the medium flows in the measuring tube, the pressure difference caused by its own kinetic energy passing through the choke (target) and has a force on the choke, and the force is directly proportional to the square of the medium flow rate
The force F received by the choke (target) is transmitted to the capacitive force sensor through the rigidly connected transmission part (measuring rod), and the capacitive force sensor generates voltage signal output
Therefore, after pre amplification, AD conversion and computer processing, the corresponding instantaneous flow and cumulative total amount can be obtained
Performance characteristics of Hehua hHB series capacitive target flowmeter
2、 Instrument output a, current output: 4 ~ 20mA; Power supply: 10-32vdc, two-wire system;
b
Pulse output: 0 ~ 1000Hz; Internal resistance 1000 Ω ; Power supply: 10-32vdc; 10mA (20mA with backlight);
c
RS232 / RS485 interface ; Power supply: 10-32vdc; 10mA (20mA with backlight);
 
Technical parameters of Hehua hHB series capacitive target flowmeter
3、 Contents and technical parameters 1
Table of main technical parameters

measured media	liquid; Gas; steam
nominal diameter	flange type 15 ~ 500mm		clamping type 15 ~ 500mm		plug in 65 ~ 3000mm
nominal pressure	0．6～42MPa		0 6～42MPa		0 6～42MPa
medium temperature	- 200 ℃ ~ + 700 ℃ or higher
accuracy	± 0 2%	± 0 5%		± 1%		± 1 5%
range	1:3 (liquid)	1:5 (liquid, gas)		1:10 (liquid, gas)		1:10 (steam)
compensation form	temperature compensation; Pressure compensation
repeatability	0 05%～0 08%
power supply	built in lithium battery (3 6V); External power supply 24VDC
output form	field display; 4 ~ 20mA two-wire system; Pulse 0 ~ 5V; RS485/RS232； GPRS wireless remote transmission
measuring tube material	carbon steel; stainless steel; It can also be provided through negotiation according to user requirements
explosion proof sign	intrinsically safe (ExiaIICT4); Flameproof type (exdiict4)
protection grade	IP65； IP67
flange specification	the specifications of the connecting flange of the flowmeter comply with the GB / T series standards, and can also be specially processed according to the user's requirements

 
4、 Precautions
  It is not allowed to directly install valves, elbows and other components that greatly change the fluid flow state at the front and rear ends of the measuring pipe of the flowmeter

If it is necessary to install valves, elbows and other components on the front and rear pipes of the flowmeter, the length of the front and rear straight pipe sections shall also be maintained as far as possible

5、 Precautions for installation and use of explosion-proof capacitive target flowmeter in dangerous places
The explosion-proof product of hHB capacitive target flowmeter (hereinafter referred to as flowmeter) has been inspected by the national explosion-proof electrical product quality supervision and Inspection Center (CQST) and conforms to GB3836 1-2000  GB3836
1 - 2000 electrical equipment for explosive gas atmospheres - Part 1: General requirements, GB3836 2-2000  GB3836
2-2000 electrical equipment for explosive gas atmospheres Part 2: Flameproof & ldquo; D & rdquo And GB3836 4-2000 electrical equipment for explosive gas atmospheres Part 4: intrinsically safe & ldquo; I & rdquo According to the requirements specified in the standard, the explosion-proof signs of the product are exdiict4 and ExiaIICT4

1
Ambient conditions for normal operation of flowmeter A
atmospheric pressure: 86 ~ l06kpa
b
Ambient temperature: - 20 ℃ ~ + 60 ℃ (8of & mdash; l40of)
c
Relative humidity of surrounding environment: ≤ 95%  RH(+25℃)
d
Flameproof flowmeter can be used in zone 1 and zone 2 dangerous places containing class IIa, IIb and IIC T1 ~ T4 explosive gas mixtures;
e
Intrinsically safe flowmeter can be applied to hazardous areas in Zone 0, zone 1 and zone 2 containing class IIa, IIb and IIC T1 ~ T4 explosive gas mixtures;
2
The user shall pay attention to the following matters when installing and using the flow meter (the following inspections shall be carried out before installation, and it shall not be put into use if it does not meet the requirements) A
There shall be explosion-proof mark and explosion-proof qualified number, which shall be consistent with the requirements of the place of use of hHB capacitive target flowmeter;
b
All parts of the flameproof shell are connected correctly and fastened reliably;
c
All flameproof parts shall be free of cracks and defects affecting flameproof performance;
d
The user shall be reliably grounded when using the flow meter;
e
Flameproof products must be used on site and maintained in accordance with & ldquo; Do not open the cover with electricity & rdquo; The principle of; During disassembly and assembly, pay attention to protect the flameproof surface and threaded flameproof surface from collision and scratch

F
The user shall not change the electrical components and system connection status of the product at will;
g
The minimum outer diameter of lead-in cable for flameproof products is & phi; 6mm；
h
The product has redundant inlets, which must be sealed with plugs provided by our company

1
After a certain period of use of explosion-proof products, aging parts must be replaced
If the sealing ring of the cable lead-in device is aged and deteriorated, it shall be replaced in time
Our company has accessories that must be purchased from our company

3
Attention shall also be paid to intrinsically safe explosion-proof products
a
This product complies with GB3836 1-2000 electrical equipment for explosive gas atmospheres Part 1: General requirements, GB3836 4-2000 electrical equipment for explosive gas atmospheres Part 4: intrinsically safe & ldquo; I & rdquo Standard, explosion-proof sign: Exia iict4, which is applicable to zone 0, zone 1 and zone 2, and places containing class IIa ~ IIC explosive gas mixtures

b
Intrinsic safety parameters: UI = 28 VDC, Ii=93 mA,   Po=0
65 W,   Ci= 0
045 uF,   Li=0
33mH  ；
c
The product shall be installed in accordance with GB3836 15-2000 electrical equipment for explosive gas atmospheres Part 15: electrical installation in hazardous locations (except coal mines)
Professional personnel shall be responsible for the installation
It is not allowed to arbitrarily replace or change the components and structures that affect the explosion-proof performance of the products that have passed the explosion-proof certification

d
This product must be used together with the qualified explosion-proof safety barrier
The safety barrier must be installed in a safe place
Its installation, use and maintenance must comply with the safety barrier operation manual;
e
When the product is used to connect intrinsically safe products in explosive environment zone 0, the power transformer supplying power to the safety barrier must comply with GB3836 Clause 8
1 of 4-2000 standard
g
Safe place [Exia] IIC , Hazardous locations ExiaIICT4 ,
h
The parameters of intrinsically safe system must follow the following matching principles:
Uo & le; Ui ; Io  & le; Ii ; Po & le; Pi ; Cc ≤ Co － Ci； Lc ≤ Lo－  Li   Cc、Lc  ： The maximum allowable total distributed capacitance and inductance of the connecting cable (or conductor) from the safety barrier to the intrinsically safe product, uo: the highest value of the safety barrier