Technical Inquiries


Low Flow Flowmeters

The Atrato inline low flow flowmeter is utilizing patented technology that enables it to operate with excellent accuracy over very wide flow ranges, across the whole span. It is a genuine breakthrough in flowmeter technology. Its rugged, clean bore construction makes the Atrato ideal for a whole range of low flow applications and its USB port allows software connectivity at literally the touch of a button.

The Atrato is a low flow flowmeter and can handle low flows from laminar to turbulent and is largely immune from viscosity. It has excellent turndown, repeatability and linearity. Accuracy is better than ±1.0% of reading. The USB connection permits the user to directly monitor the rate and total on their laptop as well as altering some of the operating parameters, such as the pulse resolution and units.

The Atrato system of low flow meters uses the well-proven time of flight measuring method, which is far more reliable and accurate than Doppler shift measurement, where reflected signals are required from irregularities in the liquid. The strong radial ultrasonic signal sends symmetrical pulses directly into the tube; the sound travelling down the pipe can be considered as a plain wave. The signal to noise ratio is remarkable as there is little background noise and high signal strengths. As the system is fully balanced at zero flows, the two signals are identical and cancel each other out. This gives a very stable zero flow condition and is the basis of the flowmeters high ratio between minimum and maximum flows. As the flow increases these signals go out of phase and this phase shift is measured to an accuracy equivalent to 250 picoseconds. In addition, the sound waves travelling down the tube in the Atrato operating system are symmetrical and as a result any changes in the fluid’s velocity profile across the pipe diameter will be averaged out by the signal as it passes from the transmitter to the receiver. It is therefore irrelevant whether the fluid velocity profile is fully formed with turbulent flow or completely laminar with a classic parabolic profile. In practice this gives the Atrato an excellent immunity to Reynolds number changes and a good high viscosity performance.

The LMX low flow flowmeter is very different than any other turbine flow meter, like e.g. beverage flowmeters. The LMX series of low flow meters are manufactured from 316 stainless steel and provide accurate flow measurement down to 4 ml/min. The Pelton Wheel is a single size, straight bladed rotor, manufactured from chemically resistant PFA and uses sapphire bearings. These bearings run in hemispherical sapphire bearing cups, which form a “floating”, low friction, precise unit. Sealed ferrites are mounted within the tips of the rotor and are sensed by the pick-up sensor suitable for high pressures. The integral upstream/downstream straight lengths ensure the correct flow profile conducive with accurate measurement in the field. With the chemically resistant materials of construction, combined with their ability to work with pressures up to 230 bar (3336 psi) and temperatures up to 100 °C (212 °F), the LMX series of flowmeters are suitable for most low flow applications



 Extreme Low Flow Ultrasonic Inline Liquid Flowmeter
Atrato Series 700
low flow meters


  • Four flow ranges: 0.002 - 0.500 l/min (0.0005 - 0.132 gpm)
                                 0.01 - 1.70 l/min (0.0026 - 0.450 gpm)
                                 0.02 - 5.00 l/min (0.0053 - 1.32 gpm)
                                 0.1 - 20.0 l/min (0.0264 - 5.28 gpm)
  • Accuracy: ± 1.0% of reading
  • Repeatability: ± 0.1% over 25 to 100% of the range
                           ± 0.5% over 0 to 25% of the range
  • Supply voltage: 10 - 24 Vdc
  • Turn-down minimal 200 : 1
  • Temperature rating: -10 - +60 °C (14 - 140 °F)
                                     -10 - +110 °C (14 - 230 °F) optional
  • K-factor adjustable; max. considering flow and frequency
  • Pressure rating: 10 bar (145 psi) / 30 bar (435 psi)
  • Outputs: Pulse NPN / PNP - to replace pulse flowmeters - max. 400 Hz
                    Programmable hardwired relay
                    Analogue 0 - 5 / 10 V or 4 - 20 mA - scalable
  • USB interface for configuration and monitoring
  • Liquid crystal display optional
  • Wetted materials; PEEK® / 316 Stainless Steel or PEEK® / Glass
  • O-ring Viton standard or Nitrile, EPDM, Silicon
  • Process connections: 3/8" John Guest, 1/2" NPT or 1/2" BSP male
  • Bi-directional with indication of positive and negative flow
  • Immune for changes of fluid velocity profile and Reynolds number
  • No moving parts


 Extreme Low Flow Pelton Wheel

Liquid Flowmeter Series LMX 

Liquid Low Flow Flowmeter


  • Flowmeter ranges: 0.0011 up to 17.2 gpm (0.004 to 65.0 l/min)
  • Accuracy: ± 2% of actual reading for 10 - 100% of range
  • Repeatability: ± 0.2 % reading over top 90% of range
  • Pressure ratings: 435, 1450 and 3336 psi (30, 100 and 230 bar)
  • Max. Temperature: 212 °F (100 °C)
  • Viscosity range: up to 10 cPs
  • Wetted parts are 316 SS, Teflon and Sapphire
  • 1/2" NPT or 8 mm OD tubing


Totalizer/ Flow Rate Indicator

for Series LMX Series 101


Flow Rate Indicator


  • Pulse input from Extreme Low Flowmeter of the LMX series
  • Readout for most engineering units
  • Analogue 4 - 20 mA loop powered and pulse output
  • Wall, pipe or panel mounted
  • 8 - 28 V ac/dc powered
  • Optional: Hazardous Area Installation


Please note: Manual data files can be quite large, please be patient while downloading.
The manuals are for information purposes only and shouldn't be used for operating the instrument