DRK139 Leakage Tester

The leakage rate tester produced by Shandong Derek Instrument Co., Ltd. is self-absorbed on the basis of reference to similar foreign equipment, and has been further improved. It is based on GB2626-2019 “Respiratory protection self-priming filter type anti-particulate respirator” 6.4 Leakage rate, a redesigned and produced device for filtering efficiency and smoke filtering performance of filter material and filter element performance. It adopts corn aerosol generator and photometer acquisition system. It adds a computer control system and improves the level of automation. It is currently a test device with complete functions, advanced technology and high level of automation among the same type of products at home and abroad.

Main Technical Requirements
The main components of the equipment; the leakage rate test bench is domestically manufactured, but the core components include aerosol generators and photometers are imported products from abroad. The air source required for the entire air circuit is external compressed air, and the power for the detection air circuit is provided by a vacuum pump. Set up an aerosol generator and one set of generating pipelines on the generating gas path; set up one set of pneumatic fixtures with cylinders, one laser dust particle counter with upstream and downstream test channels, one rotameter, and one vacuum pump on the detection gas path; One sealed cabin.

According to the Standard
GB2626-2019 “Respiratory protection self-priming filter anti-particulate respirator”

Technical Parameter
1. Aerosol type: corn oil, NaCl
2. Aerosol dynamic particle size range: (oily) (0.02-2)um, mass median diameter 0.3um.
(Salinity) (0.02-2)um, the mass median diameter is 0.6um.
3. Photometer: concentration range 1ug/m3-200mg/m3, ±1%
4. Sampling flow range: (1~2) L/min 7. Power supply: 230 VAC, 50Hz, <1.5kW
5. Appearance size: 2000mm×1500mm×2200mm
5. Inlet temperature of the test chamber: (25±5)℃;
6. The temperature and humidity of the air inlet environment of the test chamber: (30±10)%RH;
7. Electricity: Chinese standard, power supply voltage AC220V±10%, power supply frequency 50Hz±1%, pump station power 1.5kW, main engine 3kW;

Working Environment Requirements
l Inlet temperature of test chamber: (25±5)℃;
l The temperature and humidity of the air inlet environment of the laboratory: (30±10)%RH;
l Electricity: Chinese standard, power supply voltage AC220V±10%, power supply frequency 50Hz±1%, pump station power 1.5kW, main engine 3kW;
l Compressed air source requirements: flow rate of 198 L/min at 550 kPa, and the compressed air is required to be dry and clean;

Performance Characteristics
l The gas mask filter and the gas mask leakage share a set of aerosol generation system and a set of test systems. The sealed cabin is introduced to test the leakage. The whole machine and the computer are integrated in the overall test bench. The computer operation can be tested manually and automatically. The report can be stored in the computer, can be uploaded online, can be printed, the software is written by VB, the man-machine interface is easy to understand and easy to operate;
l The power source adopts an oil-free vacuum pump, which is used for suction, and adopts imported brands, which can be used continuously for a long time;
l The suction port of the photometer is connected with a HEPA high efficiency filter;
l The positive pressure blowing pipeline is equipped with system inlet low pressure protection, and SMC pressure prompt switch is adopted to prevent damage to the equipment due to low external feed pressure;
l The gas pipeline is further filtered to remove water on the basis of primary filtration, and the Q/P/S three-stage continuous filter produced by Italy HIROSS is added to perform secondary filtration to remove water;
l After the salt test is over, it needs to be cleaned before the oil test can be done
l Use one station for testing;
l The aerosol generator is equipped with a salt generator and an oil generator;
l The sealed cabin adopts a visual structure, three sides are glass windows, one of which is a sealed door, which can be opened inside and outside. There is a wireless controller inside, which can be operated by a single person from the inside;
l Diffusion air intake at the top of the sealed cabin, the air intake is a cone angle, the air outlet is placed at the bottom of the diagonal, and a degreasing cloth bag is added for degreasing;
l Upstream and downstream collection of photometer;
l A laser meter and two probes respectively collect 2 different concentration ranges, collect the concentration in the box and the mask, and detect the flow through the vacuum pump to extract the air flow from the gas path, and the size is adjusted by a manual adjustment flow meter;
l The detection control system is a PC-based integrated control system, including computer systems, I/O interfaces, various control valves, process input and output channels, counter data transmission links and other hardware and related application software. Aerosol generators, piezoelectric electrostatic neutralizers, rapid heater devices, mixers and pneumatic fixtures are designed and manufactured according to testing requirements. It can realize automatic control and data processing of the test process by operating the computer;
l Complete detection system, including occurrence concentration control system, data comparison and correction system, daily rapid inspection, quality concentration test, filter efficiency loading, filter efficiency limit loading, report storage, printing system, etc.;
l Use the acquisition card to collect, process and analyze the data, cooperate with the company to develop special software, the man-machine interface is gentle, the operation is simple, and it can be automatically and manually controlled;

Main Components of Equipment
Three-stage filter
The first level is Q level, which can remove a large amount of liquid and solid particles above 3μm, and reach the lowest residual oil content of only 5ppm, with a small amount of moisture, dust and oil mist;
The second level is P level, which can filter out liquid and solid particles as small as 1μm, and reach the lowest residual oil content of only 0.5ppm, with trace moisture, dust and oil mist;
The third level is S level, which can filter out liquid and solid particles as small as 0.01μm, and reach the lowest residual oil content of only 0.001ppm. Almost all moisture, dust and oil are removed;
Aerosol generator
The main technical parameters are as follows:
Particle size range: 0.01～2mm
Average particle size: 0.3mm
Dynamic range: >107/cm3
Geometric standard deviation: less than 2.0

The atomized aerosol generator has a large flow rate and a built-in dilution system. The user can select the number of nozzles to be activated, and each nozzle can produce more than 107 particles/cm3 at a flow rate of 6.5 lpm (pressure 25psig). The built-in dilution system is controlled by a valve and a rotameter, and the output particle concentration is adjustable. Polydisperse high-concentration aerosol. A polydisperse aerosol can be generated by atomizing a solution, or a monodisperse aerosol can be generated by atomizing suspended monodisperse particles. A variety of materials can be used (PSL, DOP, silicone oil, salt, sugar, etc.). This equipment Mainly occurs as corn aerosol.
The compressed air from the outside is divided into two ways after being stabilized and filtered. One way enters the aerosol generator and emits mixed gas containing particulates, and the other way enters the cylinder to close the upper and lower clamps to clamp the sample.
Power vacuum pump
According to the curve:
26 inHg max.vacuum
8.0 CFM open flow
10 psi max.pressure
4.5 CFM open flow
0.18kW
HEPA high efficiency filter
High-efficiency filters, with a transmission rate of ≤0.1% (ie efficiency ≥99.9%) or a filter with a count of particle size ≥0.1μm and a transmission rate of ≤0.001% (ie efficiency ≥99.999%) are high-efficiency air filters
Photometer
Photometer parameters:
Number of probes: 2
Detection concentration range: 1.0 μg/m3～200 mg/m3
Range selection: automatic
Sampling gas flow: 2.0 L/min
Purge gas flow: about 20 L/min
Appearance size: 15cm X 25cm X 33cm
The aerosol photometer is specially designed for mask quality certification and filter material testing. It uses a reliable and durable diode laser to provide a stable laser light source, which can be used for a long time without attenuation. The unique sheath gas protection system can keep the detection light room clean and low background noise, so the product requires almost no maintenance. The reliability of the design and use of this product has been verified by US government laboratories for more than 10 years. It is especially suitable for laboratory testing of mask filtration efficiency and filter material filtration efficiency. The control command of this product is very simple. It can use LabVIEW software to easily meet the requirements of test procedures and data management. Therefore, it is very convenient for users to design and build masks and filter efficiency test benches. The direction of soft probe is adjustable in 360 degrees; : Power adapter DC 24V, 5A, output: RS232 port connection (can be transferred to 485) or external printer (optional) can store 1000 sets of data.

Control volume board
Picture 9.png
With DIO and counter functions, AD buffer: 8K FIFO, resolution 16bit, analog input voltage 10V, voltage range accuracy 2.2mV, voltage range accuracy 69uV. It is used to collect the feedback value of acceleration sensor and angle sensor in real time. This card comes with a buffer function, which avoids data distortion caused by the long analysis time of industrial PCI cards and PLC systems.
4.7 Industrial Computer
4U double door industrial chassis
4U, 19 inches can be racked, all steel structure, in line with FCC, CE standards
Provide one 3.5″ driver and three 5.25″ driver positions
Optional industrial full-length CPU card or ATX architecture motherboard
Double doors on the front panel with locks to prevent misoperation, 2 USB ports on the front, providing power switch and reset button
The front panel provides a power supply and a special curved pressure beam design for the hard disk indicator, and the height of the curved pressure strip is adjustable
product description
4U, 19-inch rack-mountable, all-steel structure; 1 3.5″ and 3 5.25″ drive positions; 1 12025 double ball high-speed cooling fan at the front; Power ON/OFF, Reset
Material: 1.2mm high-quality carbon high-strength structural steel, in line with FCC and CE standards
Configuration:
Motherboard
4XPCI 4XCOM 1XLAN
CPU
Inter CPU
RAM
2G DDR3X1
hard disk
500G SATA
Accessories
300W power supply/keyboard and mouse
service
Nationwide warranty

Control Part and Post-processing
control function
l Fill in the test content manually, automatically turn on and adjust the flow to reach the target flow range, and collect the real-time values ​​of the required sensors;
l Automatically switch the pipeline according to the filled flow rate to make it reach and stabilize within the required flow rate test range to ensure the set air flow rate and its accuracy.
l Adjust the aerosol concentration as required before the test, and it can start and stop automatically at the beginning and end of the test
l You can press the “Stop” button at any time during the test to stop the test.
Data detection and processing functions
l Before the test, enter the corresponding parameters through the keyboard, and the equipment automatically collects environmental parameters (automatic collection of environmental parameters needs to be separately proposed by the user), such as atmospheric pressure, pipeline temperature and humidity, etc.; during the test, enter the air flow and powder supply through the keyboard for tests Parameters and displayed on the display
l The relevant data in the test is displayed on the test interface of the industrial computer screen. According to the test requirements, several test points in each test are automatically performed in sequence, and the test will automatically stop after the test is completed. After the test data is processed by the computer, it can be stored or output by a printer, and the filter efficiency of the filter material and the smoke filter performance of the filter components can be realized.
l The previous test data should be able to be retrieved and inquired;
l The measurement interface is friendly and has the function of man-machine dialogue;
l This test device has advanced technology, high degree of automation, and good accuracy and repeatability of test results. Therefore, it has great advantages for users’ use, installation and maintenance. It is an indispensable test equipment for air filter design and production units to develop new products, conduct research, test, and verification. It is also an indispensable equipment for the comprehensive inspection of air filter manufacturers’ products and the in-factory inspection of air filters from engine manufacturers. It is suitable for testing and product evaluation of air filter performance by testing and verification department.
Control Strategy
For the system, the controller is the control core and network hub of the entire system, and its choice is very important. At present, the control scheme based on the integrated board of a single PC and the single control scheme based on PLC occupy the leading position in the system development, but they have their own shortcomings and are difficult to replace each other.
Control scheme of integrated board based on single PC

In this kind of control application scheme, the software platform of the system can adopt windowsNT, windows CE or Linux, etc., general IO board and IO terminal board (or field bus card, field bus and remote I/O module) are responsible for the industrial control Deal with on-site. The collected input signal is received and analyzed by the PC microcomputer, and then processed by the soft PLC operating system. The control application program written by the soft PLC development system (programmer) is also interpreted and executed by the soft PLC operating system, and finally the processed signal is output to The local (or remote) control site completes the corresponding local control (or remote control) function, and its control plan and process.
The control system structure of the industrial computer combined with the I/0 board is shown above. It is mainly composed of industrial computer, digital input and output boards, analog input and output boards, buttons, switches, precision adjustable positioners and other control equipment, numerical sampling sensors, indicator lights, etc. According to the actual needs of the scene, the connection between the controlled equipment and the control system is carried out. In addition. The corresponding board can be inserted into the expansion slot to expand the control function of the system.
PC-based control refers to the use of PC software and hardware to realize the control function of PLC, and fully reflects the flexibility and high cost-effectiveness of the PC in communication, storage, programming, etc. However, compared with PLC, its shortcomings are obvious: poor stability, deterministic control cannot be achieved, and easy to crash and restart; poor reliability, the use of non-industrial standard reinforced components and rotating disks is prone to failure; the development platform is not unified, although PC control can Complete many high-end control applications, but often require different development environments. At the same time, the price of PCI boards is relatively high.
PC-based control refers to the use of PC software and hardware to realize the control function of PLC, and fully reflects the flexibility and high cost-effectiveness of PC in communication, storage, programming, etc. However, compared with PLC, its shortcomings are also obvious: poor stability, deterministic control cannot be achieved, and it is easy to crash and restart; poor reliability, the use of non-industrial standard reinforced components and rotating disks are prone to failures, and the development platform is not unified, although PC control can Complete many high-end control applications, but often require different development environments.
This control system collects parameters such as flow, temperature and humidity in the system in real time, uses industrial computer and board to process the collected parameters, and executes software control programs to complete the system control of on-off valves, regulating valves, vacuum pumps, etc. Experimental procedure. Finally, the test data report is printed and output through the printer. At the same time, the computer control system can also monitor the test status in real time, display and output alarms for abnormal conditions on site.
Test data part
This part is composed of air flow, temperature and humidity, upstream and downstream concentration, etc.

Electrical safety and protection system
l The ground wire must be well grounded, and the grounding resistance must be less than 4 ohms;
l There are protections for phase loss, undervoltage, overload, short circuit, overheating, etc. in the motor starting cabinet, and the corresponding signal output can be provided;
l The sensor signal line is connected with a shielded wire, and can be grounded at a single end according to the situation to prevent interference signals and affect the measurement. In addition, the system determines whether the sensor is working normally by means of electrical zero point;
l Use weak point control strong current method for logic control, and use relay isolation;
l All measuring pipelines are equipped with micro-pressure difference switches before and after the insulation filter to determine whether the insulation filter paper is invalid and output an alarm;
l The air circuit of the whole system is equipped with a low-pressure protection switch. When a low-pressure protection signal is detected, the system will prompt to prevent the pneumatic valve from being unable to open due to the low pressure of the air source and system failure;
External interface part
Adopt standard Modbus protocol
Modbus protocol is a universal language applied to electronic controllers. Through this protocol, the controllers can communicate with each other, and between the controllers and other devices via a network (such as Ethernet). It has become a general industry standard. With it, control equipment produced by different manufacturers can be connected to an industrial network for centralized monitoring. This protocol defines the message structure that a controller can recognize and use, regardless of what kind of network they communicate through. It describes the process of a controller requesting access to other devices, how to respond to requests from other devices, and how to detect and record errors. It has formulated a common format for the structure and content of the message domain.
When communicating on a Modbus network, this protocol determines that each controller needs to know their device address, recognize the message sent by the address, and decide what action to produce. If a response is needed, the controller will generate feedback information and send it out using the Modbus protocol. On other networks, messages containing the Modbus protocol are converted to the frame or packet structure used on this network. This conversion also expands the method of solving node addresses, routing paths, and error detection based on specific networks.
This protocol supports traditional RS-232, RS-422, RS-485 and Ethernet equipment. Many industrial equipment, including PLC, DCS, smart meters, etc. are using Modbus protocol as the communication standard between them.
Equipment matching requirements and required to complete the test
Equipment supporting
Compressed air source
The compressed air pressure is 0.5～0.7MPa, the flow rate is greater than 0.15m3/min, and the compressed air is required to be dry and clean
Power matching
220VAC, 50Hz; stable power supply above 1.5kW, guided to the high-power control cabinet with a radius of less than or equal to 2M near the equipment