First, the density compensation of steam should be scientific and accurate In order to correctly measure the mass flow of steam, the change of steam pressure and temperature must be considered, and the steam density should be compensated by the flow totalizer. The platinum resistance for measuring the steam temperature must be installed in a standard way: the temperature of the platinum thermal resistance is inserted into the center of the pipe, the platinum thermal resistance is installed at the pipe diameter 5 times downstream of the flowmeter, and the pipe position where the platinum thermal resistance is installed is taken to ensure the measurement. The obtained temperature value is accurate. In the measurement of steam pressure, it must be noted that if the pressure of the pressure tube is used, zero point migration must be carried out (because the gravity of the condensate in the pressure tube will cause a certain pressure between the pressure measured by the pressure transmitter and the actual pressure. The difference, which causes the error in the density compensation, can also be corrected in the flow totalizer. The pressure transmitter is installed at 4 times the diameter of the downstream of the steam flow meter. The valve and gasket in front of the pressure transmitter should be well-connected to ensure accurate measurement of steam pressure. If the set pressure and temperature are used for compensation, the set value should be close to the actual value, otherwise the error is very large, and it is generally not recommended.
Correctly setting the operating state of the steam flow meter in the flow totalizer is critical to the correct calculation of steam costs. For the occasions where the steam state is not well defined, it is recommended to use an intelligent flow totalizer, with platinum resistance and pressure transmitter for temperature and pressure compensation, so that the measured mass flow of steam is the most accurate.
Second, the existing vibration and electromagnetic interference should avoid the influence of the design principle of the most widely used vortex flowmeter in steam metering. It is sensitive to mechanical vibration, the measurement result is susceptible to vibration interference, and the front and rear pipe sections of the steam flowmeter should be reliably supported. Design, install vibration buffer components, such as pipeline vibration is inevitable, should use a relatively strong anti-interference ability of the steam flow meter (such as gas ultrasonic flowmeter, intelligent vortex flowmeter, differential pressure flowmeter, etc.). If there is vibration interference at the steam flowmeter, it will affect the vortex flowmeter in use to generate low-frequency pulse signals, and the steam flowmeter will transmit these pulses as flow signals to the flow totalizer to form a cumulative flow. As a result, some vortex steam flowmeters still have a certain amount of value accumulation without using steam for a period of time. This is the reason why “the flow meter is not used without steamâ€. Therefore, if the steam user does not use steam, it should also keep a record of the bottom of the watch with the steam supply unit to prevent the steam flow meter from “running emptyâ€.
Third, the steam flowmeter range ratio reasonable range ratio refers to the ratio of the maximum flow rate and the minimum flow rate that a flow meter can measure within a given accuracy range. The user should select the flow meter according to his actual usage. In theory, the range of the steam flow meter to be selected should completely cover the user's use range. Exceeding the upper and lower flow limits will cause serious misalignment of the steam flow meter. For example, a vortex flowmeter with an actual average flow rate of 5t/h should generally select a vortex flowmeter with a diameter of 150mm, but when the flow rate is reduced to 0.3t/h or exceeds 15t/h, the flowmeter will be severe. Inaccurate measurement.
Fourth, the correct installation of the upstream and downstream straight pipe sections of the steam flowmeter For the traditional vortex flowmeter, the requirements for the straight pipe sections before and after installation are 20 times the pipe diameter and 5 times the pipe diameter (this is the obstacle without the valve in front of the flowmeter). Technical requirements; there are also obstacles to increase the straight pipe section, see the manufacturer's instructions). If the upstream and downstream straight pipe sections are not enough, the steam flow in the pipeline will not fully develop and the flow velocity distribution profile will be distorted. The user can adjust the flow rate distribution of the pipe by installing a flow regulator in front of the steam flow meter or adding a straight pipe section to make the fluid at the steam flow meter fully developed. For some large diameter steam flow meters, it is more important to meet the installation requirements of the upstream and downstream straight pipe sections.
Voice Recorder (Recordable Voice Box)
Ningbo AST Industry Co.,Ltd has 17 Years Experiences to produce the Voice Recorder,Recordable Sound Box,Plush Toy Voice Recorder,Talking Box,Sound Box,Music Box,Motion Sensors ,Message Box,Voice Cards,Voice Sticker,Squeezing Box,Easy Button,USB Voice Recorders ect .we can assure you of competive price,high quality,prompt delivery and technology supporting.
1. Application :Voice Recorder is our main product,which mainly used by
plush toy,stuffer toys,Children toys,Musical toys,Children book and so
on
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2.Classification:Recordable voice recorder and Pre-record recorders
Recordable Recorder means that we can record our own message and playback it,there are 6s--240s Recording time.
Pre-record recorder--means that the clients provide their sound
files,then we programmed them into the recorder and playback them.
3.Play Mode:Push Button,Light sensor,vibration sensor,motion sensor,PIR (Infrared sensor),shadow Sensor
4.Battery:AA, AAA, AG13, AG10, AG3 and so on environmental
5.Shape and Size:Customized (OEM or ODM) or our existed standard size
6.Certification:CE ,Rohs
7.Export to: USA, UK,Canada,Germany, Turkey,Russia,Poland,Switzerland,Netherland ,Frence Hungary ,Australia,New Zealand, Brazil, Columbia,Argentina,Thainland,Singapore , Malaysia and so on
Voice Recorder
Voice Recorder, Recordable Voice Box, Recordable Sound Box
AST Industry Co.,LTD , https://www.astsoundchip.com