1、 Application Fields and Working Principles

The three parameter probe mainly provides centralized measurement of temperature, oil level, and vibration parameters for the cooling tower fan gearbox. The temperature measurement is carried out using a thermistorPt100Sensors; The oil level measurement adopts the principle of capacitive sensor; Vibration measurement using acceleration sensors can directly obtain the acceleration signal of mechanical vibration, which is integrated, amplified, bandpass filtered, and true effective value（RMS）Transformer, which converts complex vibration waveforms within the effective bandwidth into true effective values, ultimately resulting in voltage/Current driven circuit generates4-20MACurrent signal output.

2、 Troubleshooting

（1）When the three parameter number probe malfunctions, the corresponding fan's on-site junction box is opened for inspection, and no signs of corrosion or loosening of the terminals are found. The three parameter probe is disconnected from the site and the signal generator is directly used to use the temperature, oil level, and vibration circuits toDCSsend4MAThe8MAThe12MAThe16MAThe20MACurrent signal,DCSThe system is displaying normally.

（2）Clean the faulty probe with a cleaning agent,

（3）Check that the wiring circuit has good insulation to ground and that the shielding layer is grounded at a single point.

（4）Take out the probe and tap it, the vibration signal changes. Stop tapping and the vibration signal displays as0；

（5） Pour the new lubricating oil into a clean bucket, connect a three parameter probe to the outside and insert it into the bucket,

Float the probe up and down, and the liquid level changes with the movement position. When the probe is stationary, the liquid level remains stable;

（6）After removing the probe for a period of time, the oil temperature displayed was the ambient temperature at that time.

（7）Use a steel ruler to deeply mark the oil level in the gearbox and display the oil level comparison.

（8）Try replacing the probe with a new one.

3、 Fault analysis

Regarding the malfunction of the three parameter probe body, combined with the on-site usage environment and the comprehensive analysis of the probe's factory repair report, the reasons are as follows:

（1）The oil inlet small hole at the bottom of the three parameter probe is relatively small, and long-term operation of the gearbox exacerbates mechanical wear, which can easily cause oil sludge to enter and block the small hole, affecting the oil level measurement of the probe;

（2）Repair and disassembly revealed corrosion in the components of the three parameter probe circuit board. The environment where the three parameter probe is located is filled with water vapor, which may enter the circuit board with the cable interface and corrode the components, causing the three parameter probe to malfunction.

4、 Usage suggestions

（1）The factory products have undergone strict inspection and are waterproofIP68When using, try not to dismantle the cable. If dismantling is necessary on site, be sure to ensure that the cable connection is sealed properly.

（2）The size of the oil level opening at the factory is3mmRegularly clean the oil level to prevent lubricating oil impurities from blocking the small holes.