Real-Time Water Detection in Hydraulic Systems

Prevent servo valve stiction, pump cavitation, and hydraulic fluid breakdown with continuous inline water monitoring.

The Challenge

Hydraulic systems operate at high pressures with tight tolerances. Water contamination — even at levels below 0.1% — degrades hydraulic fluid performance and accelerates component wear. Many hydraulic systems are in remote or unattended locations, making continuous monitoring essential.

Servo Valve Stiction

Water causes corrosion deposits on servo valve spools, leading to sluggish response and loss of position control in precision hydraulic systems.

Pump Cavitation

Water vapour bubbles form and collapse at the pump inlet, eroding pump components and reducing system efficiency.

Fluid Breakdown

Water accelerates oxidation and hydrolysis of hydraulic fluid additives, reducing lubricity and increasing acid number. Fluid life is dramatically shortened.

Remote Installations

Hydraulic power units on mobile equipment, offshore platforms, and remote infrastructure cannot be sampled frequently enough to catch contamination events.

How Zelentech Solves It

The ZT-100 Water In Oil Monitor provides continuous, inline measurement of total water content in hydraulic systems. Unlike water activity sensors that only detect dissolved moisture, the ZT-100 measures dissolved, free, and emulsified water — catching contamination events that conventional sensors miss.

The compact, loop-powered design installs directly in the hydraulic return line or on a bypass loop from the reservoir. With 0.01% sensitivity and a 1-second response time, it provides early warning of water ingress from cooler leaks, cylinder seal failures, or condensation buildup.

The 4–20mA output can drive alarms, initiate purification cycles, or feed condition monitoring systems — enabling predictive maintenance strategies that prevent costly hydraulic failures.

Total Water Detection

Measures dissolved + free + emulsified water. Catches dangerous free water that relative humidity sensors miss.

Easy Installation

24 VDC loop powered. Installs in the return line or bypass loop — as simple as adding a pressure transmitter.

Predictive Maintenance

Continuous data feeds condition monitoring systems, enabling maintenance planning before failures occur.

Key Specifications

Measurement	Total water content (dissolved + free + emulsified)
Sensitivity	From 0.01% water content
Response Time	1 second
Power	24 VDC, loop powered (0.66 W max)
Output	4–20mA + HART
Applications	HPU systems, mobile hydraulics, press systems, injection moulding
Installation	Return line, bypass loop, or reservoir mount