OTT MF Pro Flow Meter

Operation Manual

Specifications Sheet

Product Brochure

Mobile Measurement Systems

Unit w/ Velocity Sensor, 6.5' Cable $183.75 $428.75 $1,225
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Unit w/ Velocity Sensor, Depth Sensor, 6.5' Cable $210 $490 $1,400
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Rickly USGS Top Setting Wading Rod, 4' $22.50 $67.50 $190
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The OTT MF Pro is a user-friendly, low maintenance electromagnetic current meter for cost-efficient in-stream discharge measurement. This instrument saves time in the field by automatically calculating discharge and its electromagnetic sensor head is maintenance-free, ideal for use in low-flow environments, and unaffected by large amounts of organic matter.


  • Usage Type: Spot
  • Measurement technology: Electro-magnetic
  • Parameters measured: Flow velocity and water depth
  • Product Highlights: Low maintenance magnetic - inductive probe with level measurement for reliable flow measurements. Works well in low flow and turbulent conditions, cross-sections with weed growth and pollution. Applicable in streams and conduits.
  • Measurement range: 0 … 6 m/s
  • Accuracy: ± 2% of measured value ± 0.015 m/s (0 …3 m/s) and ± 4% of measured value ± 0.015 m/s (3 … 5 m/s)


  • Discharge automatically calculated: the OTT MF pro computes discharge automatically based on USGS and ISO methods, saving time and eliminating potential for error caused by written transcription 
  • Real-time velocity: velocity is graphed in real-time on the meter's color display, allowing trends to be visualized quickly
  • Maintenance-free: the electromagnetic sensor head has no moving parts and is virtually maintenance-free
  • Versatile applications: the sensor's magnetic inductive measurement principle makes the OTT MF pro ideal for use in low-flow conditions and environments heavy in organic matter, unlike mechanical or acoustic meters
  • User-friendly handheld: a lightweight, water-resistant handheld features a full color display that is easily readable even in bright sunlight
  • Depth sensor: optionally included in the unit


The standard USGS Top Setting Wading Rod is intended for use with the Type AA and pygmy current meters. It is designed for measuring shallow streams. The anodized aluminum handle has an integral scale to indicate the correct setting of the current meter at the 0.2, 0.6 and 0.8- depth settings, which corresponds to the conventional two-position method.

This unit permits convenient setting of the current meter at the proper depth. It allows the hydrologist to quickly set the meter at the correct depth without bringing the meter out of the water. The depth of the water is read on the graduated hex main rod. When the round setting rod is adjusted to the depth of the water, the current meter is automatically positioned for the 0.6-depth method (0.4-depth position up from the streambed).

Setting the unit to half the water depth will place the meter at the 0.2-depth up from the streambed. Conversely, setting the unit to twice the water depth will place the meter at the 0.8-depth position up from the streambed. The latter two positions correspond to the conventional two-position method. The electrical lead to the current meter is supplied, and a standard plug is fitted into the handle to accept the leads from a headphone, counter or AquaCalc 5000. The commonly used two prong connector can also be supplied as required. All parts are made of stainless steel, anodized aluminum and brass.

Exact Water Depth  0.4 up from the streambed
Twice Water Depth 0.2 up from the streambed
1/2 Water Depth 0.8 up from the streambed

Rickly USGS TopSet Wading Rod