Capillary rheometerDuring use, there may be malfunctions such as abnormal sample suction, abnormal pressure, and unstable equipment operation. Production can be quickly restored through a three-step process of fault location, component inspection, and targeted repair. The following is a specific analysis:
Step 1: Fault phenomenon localization
Identifying the type of fault is a prerequisite for quickly troubleshooting, and common faults can be divided into the following three categories:
Abnormal sample aspiration
Phenomenon: Unable to sample, insufficient sample volume, or inability to measure results.
Possible reasons: Blockage of pipeline system, malfunction of pressure sensor, blockage of air path by water column.
Example: The rheometer in a certain laboratory had insufficient sample volume, and upon inspection, it was found that there was a water column in the silicone tube leading to the pressure sensor, causing the pressure sensor to malfunction.
abnormal pressure
Phenomenon: The pressure of the balanced exhaust bubble cannot rise and there is a large fluctuation in pressure.
Possible reasons: leakage of solenoid valve, damage of silicone tube, malfunction of pressure sensor or amplifier.
Example: A rheometer in a certain enterprise balances the exhaust bubble pressure very slowly. Upon inspection, it was found that the No. 3 solenoid valve was not tightly pressed onto the silicone tube, resulting in air leakage.
The device is running unstably
Phenomenon: Abnormal rotation of peristaltic pump, freezing or no numerical output during testing.
Possible reasons: Wear of peristaltic pump components, tight pump tubing, and test board malfunction.
Example: A rheometer in a certain hospital crashed during testing, and upon inspection, it was found that the central axis position was offset and the test board was damaged.
Step 2: Key component inspection
Based on the type of fault, focus on inspecting the following core components:
Pipeline and gas system
Check if the measuring pipeline is blocked (such as using a syringe to suction from the valve inlet).
Confirm whether the silicone tube is damaged or too tight (such as the wear of the peristaltic pump tube causing interruption of liquid circulation).
Verify if the pressure sensor connection is normal (such as checking if there is a water column inside the silicone tube).
Electromagnetic valves and pneumatic components
Check the action of the solenoid valve through the system maintenance menu (such as clicking on each valve to observe the tightness of the silicone tube).
Check if the screws of the solenoid valve are loose (such as valve 3 leaking air causing pressure to not rise).
Mechanical and Electronic Components
Check if the peristaltic pump components are worn (if the thickness of the four small wheels is worn by more than 75%, they need to be replaced).
Verify the position of the test board or center axis (such as reinstalling the positioning cover or replacing the test board).
Step 3: Targeted repair and verification
Based on the inspection results, the following repair measures will be taken:
Cleaning and dredging
Clean the pipeline system (such as repeatedly suctioning with a syringe to remove blockages).
Exclude the water column from the gas path (such as removing the silicone hose and throwing out the water column before reinstalling).
Clear the micropores of the sample slot (e.g. gently remove the cutting cone and use a fine needle to clear it).
Replacement and adjustment
Replace worn parts (such as peristaltic pump components, solenoid valves, test boards).
Adjust the tightness of the pump tube (such as loosening an overly tight pump tube to restore normal operation of the peristaltic pump).
Tighten the solenoid valve screws (such as tightening the No. 3 valve screw to solve the air leakage problem).
Software and parameter reset
Reset the sampling time (such as increasing the sampling time through the system menu).
Calibrate the pressure sensor (such as entering the fault diagnosis menu to check the initial value of the sensor).
Restore device default parameters (such as resetting the test board or center axis position).
Capillary rheometerPreventive maintenance recommendations
Daily cleaning: Clean the pipeline after each use to avoid protein or blood clotting blockage.
Regular inspection: Check the wear of silicone tubing, solenoid valves, and peristaltic pump components monthly.
Operating standards: Strictly follow the instructions to install and place the samples, avoiding any deviation in the central axis position.