Starting at $2,580.79
  • Usually ships in 6-8 weeks



  • Nominal diameter ranges from DN 25 to 600 (1" to 24") larger sizes also available
  • Advanced signal converter with full range of I/O 's and communication protocols
  • Diagnostic functions according to NAMUR NE107
  • Accuracy: ±0.3% +2 mm/s
  • Measures conductive and non-conductive liquids
  • Cryogenic and high process temperatures
  • Standard and straightforward applications
  • Non-viscous aqueous liquids and extreme viscous liquids
  • No moving parts
  • Full bore unobstructed sensor
  • No need for auxiliary parts


The KROHNE OPTISONIC 3400 Flow Meter is a 3-beam, inline, ultra sonic flowmeter, designed especially for measuring homogeneous conductive and non-conductive liquids, with high accuracy and reproducibility, over a long period of time. KROHNE is a main supplier for ultrasonic in-line process flowmeters for liquids with the largest installed base / proven record in terms of robustness and measurement accuracy.

The OPTISONIC 3400 Flow Meter features advanced meter diagnostics providing extensive self-checking of internal circuits and information regarding the health of the measuring sensor, but just as importantly, vital information about the process and process conditions.

Another unique feature of the OPTISONIC 3400 is the free of charge measurement of velocity of sound per acoustic path. For instance, this can supply information about pollution in the liquid, or changes in the process conditions.

Applications for the OPTISONIC 3400 include:

  • Conductive and non-conductive liquids
  • Cryogenic- and high process temperature, low and extreme high pressure range
  • Expanded applicability; for standard and high performance applications
  • Measuring aqueous liquids as well as extreme viscous oils
  • High turn down ratio; e.g. transportation pipeline measurements
  • Broad pressure and temperature range (e.g. midstream oil measurements)
  • Multiple products; e.g. allocation measurements in on/off loading
  • Water utilities in all process industries; make-up water, boiler feed water, demineralized water


Required Components

These additional components are required for the operation of your product. We strongly advise you to purchase these components unless you already own them or own a suitable alternative.


This product can be used in the following applications:

Here's how some of our customers use this product...

Hydraulic Oil Pump Testing

The Background: Our customer manufactures hydraulic pumps and seeks a means of testing those pumps.

The Problem: The customer requires both 2” and 4” meters with 3-point calibration certificates to conduct the testing. Accuracy is very important and the meters, of course, need to be compatible with hydraulic fluid.

The Solution: The customer selected Krohne OPTISONIC 3400 ultrasonic flow meters. These meters are accurate to ±0.3% with a wide range of fluids, including non-conductive fluids like hydraulic oil, is a wide range of conditions. They are ideal for product testing applications that require the highest levels

Measuring the Flow of Non-Conductive Water

The Background: Our customer is an aerospace company that needs to test their transfer systems by measuring the flow rate of non-conductive water in a 10" pipe.

The Problem: The non-conductive water limits the type of flow meters that can be used in this application.

The Solution: The Krohne OPTISONIC 3400 ultrasonic flow meter provides highly accurate flow measurements for a very wide range of fluids including both conductive and non-conductive.