Starting at $262.00
  • Usually ships in 2-3 weeks. Call for expedite options



  • Aluminum, brass and stainless steel materials available
  • Maximum pressure ranges between 600 PSIG and 6,000 PSIG
  • Fluid Media: Air & gas, hydraulic oil & 0.873 specific gravity, and water & 1.0 specific gravity
  • Flow Ranges from 0.05 to 1 GPM up to 20 to 150 GPM and from 1.5 to 12 SCFM up to 150 to 1,300 SCFM
  • ±2.5% to ±4% full scale accuracy
  • NEMA 4X enclosure


Lake Monitors variable area flow meters are accurate, dependable flow monitors configurable for numerous applications. These meters use a variable annular orifice with compression spring recoil allowing unrestricted mounting for vertical, horizontal or inverted installation. A rugged, reliable construction is used so these Lake Monitors variable area flow meters can withstand outdoor / exposed applications and frequent maintenance wash-downs.

The bodies of the Lake Monitors variable area flow meters can be ordered in aluminum, brass, or stainless steel to meet most chemical compatibility and pressure rating needs. These Lake Monitors variable area flow meters have a measuring accuracy of ±2.5% of full scale in the center third of the measuring range, and ±4% in upper and lower thirds. Lake Monitors variable area flow meters also feature a stainless steel sharp-edged orifice for durability and viscosity stability.

For more information regarding optional flow directions, including bi-directional flow and reverse flow, please contact one of our engineers today.

Basic In-Line Liquid Flow Rate Meter

The Lake Monitors basic in-line flow meters are ideal for many water applications, monitoring case drain flows, pump performance and media flows through hydraulic circuits and sub-circuits. Designed for liquids, this meter provides a visual indication of the flow rate through the meter.

Pneumatic Flow Meter

The Lake Monitors pneumatic flow meters are ideal for monitoring air compressor outputs, pneumatic tool consumption and industrial gas flows. Like the liquid version, these meters utilize a spring inlet or outlet. Straight plumbing is not required for the pneumatic meters, nor is vertical pipe mounting.

High-Temperature Flow Rate Meters

The Lake Monitors high-temperature flow meters enable flow monitoring of barrel heating fluids, thermal transfer fluids such as Syltherm® coolant flows through heat exchangers, as well as flows through hydraulic circuits and sub-circuits with elevated temps. There are two maximum temperature ratings available, 400°F (204°C) or 600°F (315°C), depending on your monitoring needs.

Flow Rate Alarms / Flow Switches

In addition to indicating the instantaneous flow rate, the Lake Monitors flow rate alarms have up to two field adjustable, dry-contact, SPDT switches. Common applications include mobile hydraulic equipment and industrial process control, ensuring sufficient flow of coolants and lubricants. These Lake Monitors meters provide economical protection by activating the onboard switch(s) when the measures flow rate differs from the adjustable set point.

Phosphate Ester Flow Rate Meter

The Lake Monitors basic in-line flow meters are compatible with aviation lubricants such as Skydrol®, as well as fire-retardant fluids such as Pydraul®, Fyrquel® and Houghton 900® series. These Lake Monitors meters include a direct-reading scale corrected for phosphate media and use the same variable annular orifice technique with compression spring recoil.

Flow Rate Transmitter

The Lake Monitors flow rate transmitters are ideal for batching, industrial process control, mobile hydraulic equipment and computer/PLC-controlled hydraulic system monitoring applications. In addition to the visual indication of the flow rate, these Lake Monitors transmitters also provide an analog 4-20mA, 0-5Vdc, 1-5Vdc, and 20-2000Hz square-wave pulse output.

Hydraulic System Test Analyzers

The Lake Monitors hydraulic system test analyzers are used to diagnose faults in hydraulic circuits, determine hydraulic horsepower and test for component wear such as hydraulic valve and cylinder leakage. The analyzer consists of a flow meter, glycerin filled pressure gauge (Style K) or a bi-metal temperature gauge/dry pressure gauge (Style T) and a precision needle-type load valve. The Lake Monitors analyzer includes a comprehensive operator's manual that describes testing of various system components.


This product can be used in the following applications: