Rotor flowmeter has a simple structure, reliable work, wide range of applications, accurate measurement, easy installation, and other characteristics, with high temperature and high-pressure resistance. Flowmeter operation in a common fault how to remove?
I. No current output
1. First of all, see if the wiring is correct.
2. Whether the LCD has a display, if there is no output display, most of the output tube is bad, need to replace the circuit board.
3. Loss of calibration value. E2PROM failure, resulting in the loss of instrument calibration data will also cause no output current, the current will remain unchanged. Solution: available data recovery operation, if it does not work, you can first set the data in the password 2000, and then set the data in the password 4011, the method is to use the hand to push the pointer calibration from RP to 100% in the data.
II. No on-site display
1. Check that the wiring is correct.
2. Check if the power supply is correct.
3. Reinstall the LCD module and check if the contact is not true.
4. For the multi-wire power supply method check if terminals 12 and 13 are connected to an ammeter or short circuit.
III. Incorrect alarm
1. Check that the deviation setting d value is not too large. 2.
2. Check that the logic function in the FUN function is correct. HA-A indicates upper limit positive logic and LA-A indicates lower limit positive logic.
3. Check the size of the alarm value setting in SU.
4. If the LCD barcode indication is correct and the output has no action, check whether the external power supply and the negative terminal of the external power supply are connected to the negative terminal of the instrument power supply.
IV. Rotameter pointer jitter
1. Slight pointer jitter: generally caused by media fluctuations. Can be used to increase the damping of the way to overcome.
2. Moderate pointer jitter: generally caused by the flow state of the medium. For gas generally due to the medium operating pressure instability caused. Can be used to stabilize the pressure or steady flow device to overcome or increase the float flowmeter gas damping.
3. Violent pointer jitter: mainly due to medium pulsation, unstable air pressure, or the user gives the gas operating state of pressure, temperature, flow and float flowmeter actual state does not match, there are large differences caused by float flowmeter over range.
V. float flowmeter pointer stopped to a certain position does not move
The main reason is that the float of the float flowmeter is stuck.
Generally due to the use of float flowmeter open the valve too fast, so that the float flies up impact stop, causing the stop deformation and will float stuck.
But also does not exclude the float guide rod and the stop ring is not the center, causing the float stuck. When dealing with the instrument can be removed, the deformation of the stopper to take off the plastic, and check with the guide rod is concentric, such as the different heart can be corrected, and then the float installed, hand pushes the float, feel the float up and down smoothly without obstruction card can be, in addition, in the float flowmeter installation must be vertical or horizontal installation, can not be tilted, otherwise, it is also easy to cause card table and bring error to the measurement.
VI. float flowmeter measurement error is large
1. Installation does not meet the requirements
For vertical installation float flowmeter to maintain vertical, the angle of inclination is not more than 20 degrees
For the horizontal installation float flowmeter to maintain the level, the tilt angle is not more than 20 degrees
Float flowmeter around 100mm space shall not have ferromagnetic objects.
The installation position should be far away from the valve reducer, pump outlet, process pipeline turning mouth, etc. To maintain the front 5D after 250mm straight pipe section requirements.
2. Liquid medium density changes are also caused by a large error of a reason. As a result of the instrument before calibration, the media are given by the user’s density for conversion, converted into the calibration state of the water flow for calibration, so if the medium density change is large, will cause a large error in the measurement.
The solution can be changed after the media density into the formula, converted into an error correction coefficient, and then the flow meter measured flow multiplied by the coefficient into the real flow.
3. Gaseous media are recommended to use temperature and pressure compensation to obtain the true flow rate due to the large influence of temperature and pressure.
4. Due to long-term use and pipeline vibration and other factors caused by float flowmeter sensing magnets, pointer, counterweight, rotating magnets, and other moving parts lose, resulting in large errors. Solution: You can first use your hand to push the pointer to verify the way.
First of all, the pointer will be pressed in the RP position, to see whether the output is 4mA, the flow rate display is 0%, and then in turn according to the scale for verification. If a discrepancy is found, the position of the component can be adjusted. Professional adjustment is generally required, otherwise, the position will be lost and will need to be returned to the manufacturer for correction.
VII. Incorrect cumulative pulse output
1. Check whether the alarm value of the one that selects the cumulative pulse output is set to zero.
2. Circuit board failure, replace the circuit board.
VIII. metal rotor flowmeter field LCD total display 0 or full range
1. Check the setting range and zero parameters in the 2000 password. Require ZERO to be less than the value of SPAN, the two values can not be equal.
2. Check whether the sampling data comes up, push the pointer by hand to see the sampling value change, if there is no change, generally for the circuit board sampling circuit failure, need to replace the circuit board.
3. Circuit board failure, replace the circuit board.