Current position > News detail
『Best Flow Meter For 0.5 To 150 Ml/Min Selection Guide』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
Best Flow Meter For 0.5 To 150 Ml/Min Selection Guide
Quick Answer: For flow rates between 0.5 and 150 ml/min, a Coriolis mass flow meter gives the highest accuracy and can handle almost any fluid. If the fluid is clean gas or liquid and you need a lower price, a thermal mass flow meter or a miniature oval gear meter often works well. Send us your fluid type, pressure, temperature, and pipe size so our engineers can recommend the right model.
Why Measuring Low Flow Rates Is Harder Than You Think
At 50 ml/min a pipe holds very little fluid. Tiny bubbles, temperature shifts, or a slight vibration can ruin the measurement. Standard electromagnetic flowmeters need a minimum conductivity and a minimum velocity. Below 0.1 m/s they become noisy. Turbine meters need a minimum flow to spin. A positive displacement meter like an oval gear can work but may leak slip at very low rates. Before you pick a meter you need to know the fluid viscosity, gas content, and if the flow is continuous or batch dosing.
We have seen this on many customer sites. A food additive plant in Thailand needed to dose 5 ml of vanilla extract per cycle. A turbine meter was too unstable. They changed to a Coriolis meter with DN1.5 connections and solved the problem immediately.
Coriolis Mass Flow Meters for 0.5 to 150 ml/min
A Coriolis meter measures mass flow directly. It is not affected by viscosity, density, or conductivity changes. The smallest models from Silver Instruments start with a flow range of 0.5 ml/min up to 6 kg/h. Accuracy can reach plus minus 0.2 percent of reading, even with bubbles or high-viscosity fluids up to 5000 cP. These meters have a wetted part in 316L stainless steel and can have Hastelloy C22 for corrosive chemicals. Output options include 4-20 mA HART, pulse, and Modbus RTU. This is the best choice for chemical injection, catalyst dosing, and high-value fragrance blending.
In practice most engineers skip the low-cost flow meters for these critical tasks. The Coriolis meter gives mass flow, density, and temperature all in one device. One oil and gas laboratory in Indonesia used a Silver Instruments Coriolis sensor to measure additives at 3 ml/min under 40 bar pressure. They required ATEX Zone 1 certification because the additive was flammable. Our meter housing comes with Ex d certification for such cases.
Thermal Mass Flow Meters for Micro Gas and Low Liquid Flows
Thermal mass flow meters sense the cooling effect of the fluid on a heated sensor. They work best for clean dry gases like nitrogen, argon, or compressed air. For liquids the fluid must be clean because a coating on the sensor ruins accuracy. Full-scale ranges start as low as 0 to 10 sccm for gases and 0.1 to 100 ml/min for liquids. A typical model for a laboratory bioreactor will measure oxygen flow at 20 ml/min with plus minus 0.5 percent full scale accuracy. The response time is fast, often under 1 second.
Because thermal meters have no moving parts they need almost no maintenance. A medical device manufacturer in Mexico uses a Silver Instruments thermal liquid flow meter to control the saline flow into a test fixture at 80 ml/min. The device outputs 4-20 mA and has a small internal diameter of 1.6 mm. The price is lower than a Coriolis and installation is simple: just screw it into a fitting and connect two wires.
Miniature Oval Gear and Other Positive Displacement Options
Oval gear meters work well for clean lubricating fluids like diesel, light oil, or solvent. For 0.5 to 150 ml/min you need a micro oval gear with very small chambers. A typical model from Silver Instruments has a flow range of 2 to 200 ml/min and operates at pressures up to 64 bar. It gives a pulse output, easy for batch control. Accuracy is plus minus 0.5 percent of reading when the fluid viscosity stays above 1 cP. If you try
We got an inquiry last year from a fragrance filling company in Brazil. They needed to fill small bottles of perfume at 30 ml per cycle. Oval gear meter repeatability was 0.1 percent at that rate, which was enough to reduce material waste by 2 percent annually. They preferred the simple mechanical register over complex electronics.
Ultrasonic and Electromagnetic Flow Meters at Micro Flow Rates
Ultrasonic clamp-on flow meters cannot measure flows as low as 0.5 ml/min in almost all cases. The minimum pipe size is usually DN15 and the minimum velocity near 0.1 m/s. That gives a lowest flow of about 40 ml/min in ideal conditions, rarely repeatable. Small inline ultrasonic meters with a piezo element can reach down to 10 ml/min for deionized water but are sensitive to bubbles.
Electromagnetic flow meters require conductive fluids, minimum 5 microS/cm. Below 0.1 m/s velocity the signal is buried in noise. Even with a DN2 flow tube the lowest steady range is around 50 ml/min. For desalination plant chemical dosing at 100 ml/min a miniature electromagnetic meter can work if the chemical is conductive enough. Silver Instruments offers a DN4 version for such niche applications.
Selection Decision Table and Practical Advice
Here is a direct breakdown based on what we ship to factories in Asia and the Middle East:
For any fluid where mass flow matters and error is costly: Coriolis meter.
For clean dry gas micro flow: Thermal mass flow meter.
For clean oil, diesel, or solvent batches up to 200 ml/min: Micro oval gear meter.
For conductive water-based additive at 50 to 150 ml/min: Mini electromagnetic meter if budget is tight.
For non-conductive clean liquids at 10-50 ml/min: Inline ultrasonic micro meter.
We usually ask our customers three questions before quoting: What is the process fluid and its viscosity? What is the minimum, normal, and maximum flow rate? What pipe connection size and pressure rating do you need? This cuts the selection time in half.
FAQ: Low Flow Meter Selection (0.5 to 150 ml/min)
Q: Can I measure 2 ml/min of diesel with a thermal mass flow meter?
A: No. Thermal mass meters need a clean, non-coating fluid. Diesel may leave deposits. Use a micro oval gear meter instead.
Q: What is the smallest pipe size for a Coriolis meter at 10 ml/min?
A: Silver Instruments can supply a Coriolis sensor with DN1.5 (1/16 inch) process connections. The internal tube diameter is around 0.8 mm.
Q: Do I need a flow conditioner for a micro flow meter?
A: Usually no. At these tiny flow rates the meter itself provides enough pressure drop to create a stable velocity profile. Just keep 10 pipe diameters straight run upstream.
Q: Can the same meter handle both liquid and gas at 0.5 to 150 ml/min?
A: No single meter works well for both phases at such low rates. A Coriolis meter can measure both in theory but the density change is extreme. You will need two different ranges or two meters calibrated for each phase.
Q: How do I send an inquiry and get a quote fast?
A: Email our team with the fluid name, flow range in ml/min, pressure in bar, temperature in degrees Celsius, and pipe connection size (e.g., 1/8 inch NPT). We will reply with a recommended model, datasheet, and price within 24 hours.
Need a reliable flow meter for your low-flow process? Send us your pressure (bar), temperature (deg C), pipe size (DN), and flow range today. Our engineers will select the right technology from our stocked inventory in Australia and China so you do not waste time testing the wrong meter.