Are mass flow meter sensors that delicate?
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A few days ago, I posted a question: do mass flow meters exhibit excessive errors at low flow rates? At that time, a large error was detected in the flow meter. Following the advice of the manufacturer’s sales engineer, it was suspected that the blockage of the measurement tube was the cause of the problem. The flow meter was cleaned with clean water and then refilled with fluid; yet its instantaneous flow rate continued to show as 0. Today, the manufacturer’s sales engineer came to the factory and checked it, saying that the sensor was damaged beyond repair. Is this sensor that delicate? Could it be a problem with the circuit board or wiring, which prevents the sensor’s signal from being transmitted to the main board? I need an expert to help answer this.
Could you please provide a detailed description of the operating conditions, model, fault situation?
It’s the E+H 80F80 model, used for measuring 37% formalin solutions; the temperature of the material is around 35°C. It has been working properly until recently when measurement errors started to occur. When trying to add about 600 kilograms of material, it seems that the filter before the pump was slightly clogged, resulting in a flow rate of only 3 tons per hour. Based on the flow meter readings, too much material was added – approximately 100 kilograms more than intended. Since formaldehyde tends to polymerize, there was concern that the flow meter might get clogged; so it was taken apart and rinsed with water, and after reinstalling it, no flow reading was displayed.
There is one situation; it’s not clear whether it has an impact on the flow meter: the formaldehyde purchased earlier was colorless and transparent, while the formaldehyde this time is yellow. It turns out that this yellowing is caused by rust. Could rust get trapped inside the flow meter, preventing the sensor from functioning properly?
It’s likely that there’s a high degree of deception here; without sending it back to the factory for inspection, it’s impossible to know whether it’s really broken. We send our products back to the manufacturer so that their technicians can disassemble them and conduct an analysis
There are two aspects to determining whether a sensor is functioning properly. One is to enter a special password and check whether the values of the excitation current and frequency in the analysis menu fall within the normal range. The other is to examine the coil impedance after the power is cut off and the connection is broken; if there are no issues with either of these, it cannot be concluded that the sensor is defective. Conversely, if there are problems, then it can be determined that the sensor is faulty. It depends on whether your service engineer has issued the corresponding report
I also have some doubts regarding the E+H mass flow meter, which I would like to discuss: The sensor of a mass flow meter used for measuring dilute formaldehyde was determined to be damaged, but why could it still function properly when tested with water as the medium? Furthermore, if the flowmeter sensor is replaced and installed in another location, can its flange be cut off and then replaced with another similar flange by welding?
The sales engineer called their technical support team on the spot; based on the error code “587” displayed on the flow meter, he concluded that the sensor was damaged and said there was no need to send it back to the factory for repair as it was not worth it.
What you’re talking about is too technical; can one’s own instrumentation engineer carry out the checks? How to do it? The sales engineer called their technical support team on the spot; based on the error code “587” displayed on the flow meter, he concluded that the sensor had failed, and no report was issued.
Calibration was done using water as the medium, but there is no flow display either. The sales engineer said that the sensors of the flow meters are completely sealed, and they generally come directly from abroad; in China, only other accessories are installed alongside them. Cutting the flange must be risky, right?
Yes, what he said is correct. It is recommended to have a manufacturer’s engineer visit the site. . . . PS: Which factory are you from?