±0.5% of reading
Accuracy
0.1%
Repeatability
4-20 mA, pulse
Output
RS485 Modbus-RTU
Communication
DEFINITION & OVERVIEW
What is a Micro Gear Flowmeter?
A micro gear flowmeter is a positive displacement meter. Inside a machined chamber, a pair of precisely matched gears turns as the liquid passes through. Each turn traps and moves a known volume, and a non-contact sensor counts each gear tooth. Count the teeth and you know exactly how much liquid went by.
That makes it a natural fit for reagent dosing lines, where small, accurate and repeatable volumes matter more than a wide turndown range. A flotation circuit may use only a trickle of collector or frother, so a meter that reads those small flows cleanly gives operators something they can actually dose against.
John Finlay's unit is accurate to ±0.5% of reading with 0.1% repeatability and 0.001 unit resolution. It outputs 4-20 mA, pulses, and two switch signals; speaks RS485 Modbus-RTU; and has an SS304 housing with an LCD display. It is the measuring element of our Flotation Reagent Dosing System, and it suits any other small-volume liquid line in the plant.
Counts Real Volume
Gears divide the flow into fixed volumes and a sensor counts every tooth, so the reading follows the liquid actually delivered.
Made for Small Flows
Designed for reagent lines where a small, repeatable volume matters more than turndown.
Talks to Your Control System
4-20 mA, pulse, switch outputs and RS485 Modbus-RTU, with a local LCD for the operator at the dosing skid.
Parameter | Value |
|---|---|
Accuracy | ±0.5% of reading |
Repeatability | 0.1% |
Resolution | 0.001 unit |
Power Supply | 9-26 V DC |
Output | 4-20 mA (2, 3 or 4-wire), pulse, two switch outputs |
Communication | RS485, Modbus-RTU |
Probe Temperature | -40 to +140 °C (high-temperature version to +200 °C) |
Housing | SS304, IP65, LCD display |
KEY FEATURES
Key Features & Performance Highlights
Accuracy Stated Plainly
±0.5% of reading means the error is a percentage of the flow actually passing, which is what you want on a small dosing line. Repeatability of 0.1% means the same dose delivers the same reading, shot after shot.
Fine Resolution
A resolution of 0.001 unit lets the control system see very small changes in dosing, instead of waiting for a larger total to accumulate.
Every Output You Are Likely to Need
4-20 mA in two, three or four-wire form, a pulse output, two switch outputs and RS485 Modbus-RTU communication. Connect it to a PLC, a dosing controller or a SCADA system without extra converters.
Fits Your Existing Control System
The signal goes straight into the central control system, so there is no separate monitoring screen to watch. Alarms and trends appear where the operator already looks.
Built for the Plant Floor
SS304 housing rated IP65, an LCD for local reading, and an M12 connector with a 2 m lead for quick, clean electrical connection.
WORKING PRINCIPLE
How the Micro Gear Flowmeter Works
It measures volume by counting, not by inferring.
Liquid Enters the Chamber
Reagent flows into a machined measuring chamber.
Gears Divide the Flow
A pair of precisely matched gears turns as the liquid passes, and each turn moves a fixed, known volume.
Sensor Counts Each Tooth
A non-contact sensor counts every gear tooth, with no mechanical link to the electronics.
Electronics Convert to Flow
The count becomes flow rate and total volume at ±0.5% of reading, shown on the LCD.
Signal to the Control System
4-20 mA, pulse, switch outputs or Modbus-RTU carry the result to the dosing controller or PLC.
TECHNICAL SPECIFICATIONS
Micro Gear Flowmeter | Full Specification
Parameter | Specification |
|---|---|
Principle | Positive displacement, matched gears, non-contact tooth counting |
Accuracy | ±0.5% of reading |
Repeatability | 0.1% |
Resolution | 0.001 unit |
Power Supply | 9-26 V DC |
Output | 4-20 mA (2, 3 or 4-wire), pulse, two switch outputs |
Communication | RS485, Modbus-RTU |
Probe Temperature | -40 to +140 °C (high-temperature version to +200 °C) |
Housing | SS304, IP65, LCD display |
Electrical Connection | M12 connector with 2 m lead |
COMPARISON
Micro Gear Flowmeter vs. Electromagnetic Flowmeter
Micro Gear Flowmeter
Electromagnetic Flowmeters
Applications of the Micro Gear Flowmeter
Wherever a small liquid volume has to be measured accurately and repeatably.
Flotation Reagent Dosing
Measures collector and frother dosing lines, the core duty of our Flotation Reagent Dosing System.
Batch and Totalized Dosing
Pulse output and 0.001 resolution suit batch dosing and running totals.
Heated Reagent Lines
The high-temperature version reaches +200 °C for lines that run hot.
Dosing Controller Feedback
Feeds a dosing controller or PLC with flow in 4-20 mA, pulse or Modbus-RTU.
Other Small-Volume Liquid Lines
Any plant line where small, repeatable volumes matter more than turndown.
About John Finlay
Flow Instrumentation Supplier in India
Why John Finlay?
±0.5%
Accuracy of Reading
With 0.1% repeatability, a dosing reading can be trusted shot after shot.
130+
Coal Washery Projects
Completed EPC projects worldwide, including Asia’s largest coking coal washery at 30 MTPA.
EPC
Full Circuit Supply
Supplied as part of a complete instrumentation and automation offering across the coal preparation flowsheet.
IN
India-Based Support
Manufactured at Hefei John Finlay Mining Equipment Co., Ltd. and supported locally in India for installation, commissioning, spares and service.
Micro Gear Flowmeter | Frequently Asked Questions
Common questions from process engineers specifying small-flow measurement.
A pair of precisely matched gears turns inside a machined chamber as liquid passes through. Each turn moves a known volume, and a non-contact sensor counts each tooth, so the meter measures volume directly.
±0.5% of reading, with 0.1% repeatability and 0.001 unit resolution. Because accuracy is stated as a percentage of the reading, the error scales with the flow instead of being fixed against a full-scale value.
4-20 mA in two, three or four-wire form, a pulse output and two switch outputs, plus RS485 Modbus-RTU communication. Power is 9 to 26 V DC.
The probe works from -40 to +140 °C, and a high-temperature version reaches +200 °C.
Yes, reagent dosing lines are its main duty, where small and repeatable volumes matter more than turndown. See our Flotation Reagent Dosing System.
Electromagnetic meters suit larger conductive lines such as slurry and water. A reagent dosing line is small and may not be conductive, so a positive displacement meter is the better match. See our Electromagnetic Flowmeter for the larger lines.
Need accurate readings on your small reagent lines?
Our engineers can help you choose the right meter for each dosing point.
Talk to an ExpertRelated Equipment
Flotation Reagent Dosing System (S3)
The dosing application this meter is built for.
Flotation Machine
The flotation equipment these reagent lines feed.
Electromagnetic Flowmeter
For larger conductive slurry and water lines
Non-Full-Pipe Electromagnetic Flowmeter
For partly filled lines.
Instrumentation Overview
All John Finlay instruments and control systems.