Daily maintenance (1)
Only need to periodically check the instrument, check the environment around the instrument, remove the dirt, ensure that no water and other substances are inspected, check whether the wiring is good, check whether there is a new strong electromagnetic field device near the instrument or a new installed wire across the instrument. If the measuring medium is easy to contaminate the electrode or precipitate or scale in the measuring tube wall, it should be regularly cleaned and cleaned.
Folding fault finding
After the flowmeter starts to be put into operation or is put into operation for a period of time, it is found that the instrument is not working properly. First, check the external condition of the flowmeter, such as whether the power supply is good, whether the pipeline is leaking or is in a state of non-full pipe, whether there is air bubble in the pipe, whether the signal cable is Damage, converter output signal (ie rear position meter input loop) is open circuit. Remember to blindly disassemble the flowmeter.
Flowmeter product features:
Frequency programmable low frequency rectangular wave excitation improves stability of flow measurement and low power loss;
The new 16-bit ultra-low power microprocessor with FLASH memory has high integration, fast calculation speed and high calculation accuracy.
Full digital processing, strong anti-interference ability and reliable measurement;
Ultra-low EMI switching power supply, suitable for power supply voltage variation range, high efficiency, small temperature rise; good EMC performance;
Chinese and English menu operation, easy to use, easy to operate, easy to learn and understand;
High definition backlight wide temperature LCD display;
It can perform bidirectional flow measurement and bidirectional total accumulation; it has automatic range switching function, which can effectively improve the measurement accuracy of analog current and frequency output, especially suitable for occasions where the diurnal flow range changes greatly and needs to send control signals; flow measurement range Up to 1500:1;
There are three totalizers inside, which record and display the forward cumulative amount, the reverse cumulative amount and the accumulated difference integrated amount, which are convenient for fluid metering and custody transfer;
Provide isolated or non-isolated RS485/RS232C digital communication interface, and support fieldbus communication modes such as MODBUS, PROFIBUS-DP and HART;
Constant current source fluid resistance measurement can accurately measure the internal resistance of the electrode signal in the case of long-line transmission. It can be used not only to determine whether the fluid in the sensor is empty or not, but also to identify abnormal phenomena such as contamination and coverage of the electrode, and to provide cleaning for the user. Fault processing information such as electrodes;
Selection of measurement types for special industrial and commercial users
I. Introduction
At present, there are some special users in the supply of industrial and commercial users. On the one hand, the gas points are more dispersed, and the amount of gas used in a single combustion device is small (generally 2 to 9 m3/h); on the other hand, the total amount of gas used is Very large, there are many problems with the accurate measurement of the natural gas supply of such users. This type of industrial and commercial users have multiple fuel appliances with different gas consumption. Different gas consumption at different time periods brings certain difficulties to the accurate measurement of natural gas. Under the condition of satisfying the maximum gas consumption, it cannot be measured under the condition of small flow. The problem.
1. Case 1: A large shopping and entertainment mall
The mall has 22 gas points distributed on the second, fourth and fifth floors. In order to ensure the accuracy of natural gas measurement, the gas supply system has a master meter (turbine flow meter Q650) and 22 sets of compensation functions. As a metering table, the flow meter usually has a gas consumption of about 400m3/d and a holiday of about 800m3/d. It is found through the data collection that the total number of meters and sub-meters is about 17m3 per day; in the initial 54d. The cumulative gas consumption of the master meter and the minute meter differs by 11511.80 m3.