Problems with mass flow meters
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Yesterday, one mass flow meter developed a problem; the meter has two milliampere outputs, with the second output representing temperature. The temperature displayed on the host unit is -12.8 degrees, but the actual temperature is around 60 degrees; the gauge on site shows around 58 degrees. Both outputs of the measuring instrument are around 2 mA. The alarm records indicate a sensor failure – so why does the gauge on site still show an accurate reading? (The mass flow meter is a Rosemount 2700)
It is recommended that you remove the core processor from the sensor; there is a nine-pin connector inside. The three pins standing upright are thermal resistors, while the other six pins correspond to right detection –+, left detection –+, and drive coil –+. Measure the resistance values of each pin as well as their resistance to ground. Using a multimeter, check that the resistance of each pin to the casing is greater than 5M ohms; the resistances of the other pins should be between 100 and 200 ohms. Verify whether these values meet the requirements. If not, the sensor is likely damaged, and in that case, you will need to contact the manufacturer.
The core processor is also prone to failure