I have used data loggers for some time, and have found they are an essential tool, which helps me fault find hydraulic systems problems. When you don’t know the pressures in a duty cycle of a hydraulically operated machine, you cannot understand how the circuit works. One example where we could not have identified the cause of a problem was when were replacing rod seals on a cylinder regularly.
We took pressure traces of the machine duty cycle and saw a negative pressure when the cylinder had fully retracted. This was causing the damage to the cylinder rod seals, but why was there a negative pressure? We thought that the proportional control valve must have been fully open when the cylinder was retracted, so what controlled the valve? Limit switches should have slowed the movement and reduced the flow before the cylinder fully retracted, so the valve should have been partially closed. When we looked, we discovered that the limit switch bracket had been damaged and the limit switch was out of position. We fabricated a new bracket and positioned the limit switch. Taking new traces we discovered that the negative pressure had gone and the pressure traces looked good. 2 years later and we had not replaced any cylinder rod seals.
We could not have seen the negative pressure without the data logger traces. To be successful at fault finding in hydraulics you need information and data loggers can provide useful information.
