The time difference ultrasonic flowmeter

Products overview:
ZWS - 100 - f series of time difference ultrasonic flowmeter are introduced advanced flow measurement techniques and low cost to implement encapsulation at an organic whole, can be directly installed on the measuring point.No moving parts, without daily maintenance, instrument on the microprocessor provides * digital signal encoding and cross-correlation detection procedures, can provide long-term drift measurement.But for almost all clean uniform liquid flow body.Widely used in industrial field of online measurement of various kinds of liquid flow rate.

Second, the working principle:
ZWS - 100 - f seriesTime takes advantage of the low voltage type ultrasonic flowmeter, multiple pulse jet lag principle, the use of high precision and super stable double balance emission signal difference, difference receive digital detection technology to measure the direction of the downstream and upstream sound wave transmission time, according to calculate the velocity of jet lag.When ultrasonic beam propagation in the liquid, the flow of the liquid produce small changes will make the travel time, the travel time is proportional to the liquid flow rate, the change of zero flow, two sensors in the time required to transmit and receive sound waves is exactly the same techniques for actual measurement of zero flow (*).Medium flow, the flow direction of sound wave transmission time is greater than in the direction of flow of sound wave transmission time.

Applications:

ZWS - 100 - f seriesTime difference ultrasonic flowmeter is widely applied in industrial field of each kind of liquid in the online traffic measurement, which the host is divided into standard wall hanging type, tray type, hanging type explosion-proof, sensors can be divided into outer bound type, insert type, pipe sections, etc., the use of different field in order to meet user needs.

Four, measuring medium:
1, type: tap water, sea water, industrial sewage, various oil, acid alkali, alcohol, beer can support such as ultrasonic single homogeneous liquid;
2, temperature: 0 ℃ ~ 160 ℃;
3, turbidity, 10000 PPM or less, and the bubble content is small;
4, velocity: 0 ~ + 30 m/s;
5, flow: positive and reverse bidirectional measurement, and can be measured net flows;

Five, the working environment:
1, the temperature of the host: - 30 ℃ ~ 80 ℃;
2, flow sensor temperature: - 40 ℃ ~ 160 ℃;
3, temperature sensor temperature: selected according to user's requirements;
4, host, humidity: 85% RH;
5, flow sensor, humidity: can work immersed depth of 3 m or less;
6, ultrasonic flow power: AC220V DC8 ~ 36 v or AC7 ~ 30 v.

Six, the main features:
1, high precision measurement
Linearity is better than 0.5%, the repeatability accuracy better than 0.2%, measurement precision is better than that of + / - 1%;
2, strong memory function
Automatic memory before 512, 128 month before, in the first 10 years of accumulated flow, automatic memory before 64 calls and interruption time and flow, automatic memory 32 days before the working state of the flow meter is normal;
3, large measuring range
Choose different types of sensors, which can realize caliber DN15 ~ DN6000mm pipe flow measurement;
4, high reliability
With low voltage, pulse emission circuit, measuring precision, service life and reliability greatly increased;
5, support Chinese and English menu
Different versions of the flowmeter, can support Chinese or English menu, convenient and quick;
6, strong anti-interference ability
Adopt double balanced differential signal transmitting and receiving circuit, effectively resist frequency converter, television tower, strong interference sources such as high tension line.
Seven, the technical parameters:
1, the measurement precision, better than 1%, repeatability, better than 0.2%;
2, measuring cycle: 500 ms (2 times per second, 128 groups of data per cycle).
3, working power supply: 85 ~ 264 vac / 24 VDC isolation (F4 type 8 ~ 36 VDC);
4, zui flow velocity: 64 m/s (velocity resolution of 0.001 m/s);
5, show: 2 x 10 Chinese characters backlit LCD display instantaneous flow and the positive and negative, cumulative net flow and flow velocity, etc.;
Touch 6, operations: 4 * 4 keyboard (F4 host magnetic 4 buttons) operation;
7, signal input:
3 road 4-20 ma analog input, accuracy of 0.1%, can input pressure, liquid level, temperature and so on;
2 way three-wire system PT100 platinum resistance;
8, signal output:
1 road isolated RS485 output;
1 road 4-20 ma, or 0 to 20 ma output;
1 OCT road isolation (pulse width between 6 ~ 1000 ms programmable, the default 200 ms).
1 road relay output (pulse width 200 ms);
9, communication protocol: cardiac MODBUS protocol, M - BUS protocol, SONY card FUJI extended protocol, and compatible with the domestic similar products of other manufacturers communication protocol;
10, other functions: cardiac automatic memory before 512 days, 128 months before, in the first 10 years of positive/negative/net cumulative flow;
Automatic memory before 30 times on power, time and flow rate and flow rate can be realized automatically or manually adding, can be read through the MODBUS protocol.
Programmable batch (quantitative) controller, fault self-diagnosis function;
Can be transmitted to the code file to realize software upgrade;
11, protection grade: the host sensors IP68 IP65, explosion-proof host IP68;
12, explosion-proof grade: EXd Ⅱ BT4.
Eight, the influence of air content on the measuring accuracy:
Gas content has a great influence on the measurement data.Insoluble gases very low acoustic impedance, may cause beam scattered.Air content is big, will reduce the intensity of the acoustic signal.Vaer characterization of the parameters of the air content, the flowmeter is usually state Vaer < 50, our factory is used to measure the two meter transducer of chemical fiber circulating water installation position is not good, there is a large air before a pump pool, pump is apart from the straight pipe is less than 10 d between transducer, measurement data is not stable;Another pump from the straight section between transducer meet the requirements of the 10 d, measurement data is stable.Due to the need of process operation, circulation water every half month to join a stripping agent, air content in the pipe.Straight pipe before the pump to the transducer is too short, bubble serious influence measurement, meter stop working, and it lasts about two days.Conditions back to normal, the meter automatically return to work (in order to confirm this situation, and at the same time, we used doppler type ultrasonic flowmeter measurement, can work normally, and indicating content).
Therefore, to eliminate the air content, must ensure that the length of the straight pipe before and after the transducer.
Nine, the influence of coupling agent on measurement accuracy:
In order to ensure good contact with transducer and pipe, install transducer needs pipe surface evenly coated a layer of coupling agent, the general thickness of 2 ~ 3 mm.Should be the bubbles and particles out inside the coupling agent, the launch of transducer surface should be closely on the pipe wall.Measurement of the circulating water flow meter is installed in the water well mostly, installation environment humidity, sometimes under water, if choose average coupling agent, in a short time will be failure, affect measurement accuracy.Therefore, you must choose special waterproof coupling agent.
Validity of using coupling agent, according to producers, general coupling agent can be used for 18 months, therefore, in order to ensure measurement accuracy, every 18 months should replace the transducer, the change of coupling agent.
Ten, sensor installation steps:
1, choose to have enough length of straight pipe position, must be the new pipeline, no rust, easy to operate.
2, clear the clutter and on the pipeline corrosion, using grinding Angle grinder abort rust.
The launch of 3, on the sensor surface with plenty of coupling agent (such as butter, vaseline, etc.), besmear coupling 4, mixture rule out is the purpose of the sensor emission surface and air between the external surface of the pipe.
5, special remind: should avoid sａnd and debris into the middle.
6, horizontal pipe wall upside may remain some bubble, in the selection of pipe should be installed on the tangent to the pipe on the side of a vertical surface.
Eleven, signal intensity:
Refers to the received signal strength after amplification of ultrasonic signal amplitude, with 3 digits said: [000] is not detected any signal;[999] zui refers to the received signal.
Although signal between 500-999 meter can work, but the stronger signal strength can get good results, so users should adjust the signal of the sensor to receive to zui.
Suggestions according to the following methods of operation to get larger signal strength:
1, if measured flow numerical instability, when signal strength is below 700, to choose a better location measurement.
2, the outer surface of the polishing pipe carefully, some slightly more coupling agent.
3, slightly adjust the relative position of the sensor at the same time observe the flow meter of received signal strength, parked in the signal zui big place, at the same time also want to check if the distance between the sensor can satisfy the demands of M25 window display.
Signal quality (signal good degrees) :
Flowmeter signal quality is to use Q value.Q value means the higher signal-to-noise ratio (SNR) of an acronym, of course, is more accurate, the measured data of the Q values should be between 600-900 range, the higher the better.

Twelve, optional tied outside sensors:

Outer bound type sensor is to bundle sensors directly on the outer surface of the pipeline under test so as to realize the flow measurement of an installation, has has nothing to do with the pipe diameter, installation is simple, no production, no pressure loss, etc.

13, optional insert sensors:

Insert type sensor is refers to the hole on the pipeline to be tested using special tools in online punching without shutdown, so direct contact with the sensor and measured medium so as to realize the flow measurement of an installation, the sensor has solved the outer bound type sensor in measuring scale thick line to receive the signal and measurement signal attenuation problem for a long time, has not stopped production installation, maintenance free, has nothing to do with the pipe diameter, pressure loss, etc.
Pipe material is carbon steel or stainless steel can be directly welded installation, for not directly welded pipe, such as cast iron, cement, glass fiber reinforced plastic, PVC pipe should be equipped with the factory production of special pipe hoop before installation, to prevent leaking, when you place an order, please provide accurate measured pipe diameter or circumference.

14, selection of coding:

Example:,ZWS-100F1-200-M1-0-1-A-L5；
Explanation: the pipe diameterDN200mm,The standard standardM1Sensors, no input,4-20mAThe output,220VACPower supply, signal cable5mX 2。

15, design selection and ordering information:

1, products: specify model standard, if any, please live in wei sales hotline advisory prices, details!

2, technical support, if not specified product specifications, please put the working condition of requirements, design drawings, technical specifications, to us.

3, product orders for parameters: size (DN), nominal pressure (Mpa), temperature (℃), the connection way (flange, etc.) to the clamp.

4, offer confirmation: the company provide price list and technical standard specifications to customers to confirm, in the technical aspects to confirm before you draw up a contract.

5, quality requirements, quality standards, the supplier is responsible for the quality conditions: according to the relevant state quality standards.

After-sales service commitment:

1, from the date of signing of the contract, I in the way provided for products of the company offers free maintenance and maintenance service, commitment to lifelong maintenance service;

2, jiangsu wei measurement and control instrument co., LTD. Sales manager will be in regular contact with customers, understａnd the usage of products, and solve the problems of the customers to use in the process of produce, free of charge to provide technical support;

3 the man-made damage is found, the warranty period, our company is responsible for the maintenance, and the resulting maintenance fee;

4, product quality problems or are not satisfied with product, the user can choose unconditional return, wei tt&c don't charge any fees, appear quality problem, bear the freight back and forth.