Surface Velocity Radar (SVR)

Handheld water flow sensor

Part # 51155

The Stevens SVR is a hand‐held Surface Velocity Radar (SVR) gun specifically designed to measure the surface velocity of water—great for use in streams and rivers.

The SVR is powered by rechargeable batteries, making it easy to measure surface flow anywhere. An LCD screen on the back of the unit displays flow readout while in operation, and is also used to configure the device.

The radar gun features a tilt sensor system, which internally compensates for the cosine angle effect of the vertical (pitch‐down) angle of the gun to the target. It is not necessary to manually set the tilt sensor. Software compensates for the horizontal (yaw) angle created when the gun is aimed at a target from an angle greater than 10° from the parallel alignment of the gun to the target.

  • Handheld unit is easy to use anywhere
  • High-accuracy liquid surface flow measurement
  • 0 - 60° measurement angle with automatic angle compensation
  • Instantly view measurements on back LCD screen
  • Imperial or metric output units

NOTE: The SVR is available for international customers only. Not available for the US domestic market.

Technical Specifications



Liquid surface flow radar


±0.1 f/s (±0.3 m/s)

Measurement capability

Will measure flow speed towards user or away from user

Operating temperature

-22 °F to +158 °F (-30 °C to +70 °C)

User interface

LCD screen with backlight, controls (buttons) on back of unit

Cosine - vertical

Tilt sensor automatically compensates for vertical angle

Cosine - horizontal

0 - 60° in 5° increments


10 levels

Maximum humidity

90% relative humidity @ +98.6 °F


Rechargeable NiMH batteries or detachable 12V power cable with automobile outlet plug

Housing material

Rugged ABS polycarbonate blend


10.25” (H) x 3” (W) x 7.25” (L) (26.30 cm H x 7.62 cm W x 18.41 cm L)


2.1 lbs (0.9 kg)


Two years parts and labor

Measurement specifications

Speed selection

mph, km/h, feet-per-second (fps, default), meters-per-second (m/s)

Min. flow speed

0.3 fps (0.3 m/s)

Max. flow speed

30 fps (9.1 m/s)

Microwave specifications



FCC Identifier



24.150 GHz

Beam width




Power density

less than or equal to 1 mW/cm2

Power output

7 mW nominal

Power consumption


1,050 mA

Antenna ON no target displayed

1,700 mA

Antenna ON anything displayed

1,720 mA

Antenna OFF segment check "888"

1,160 mA

Antenna ON segment check "888"

1,800 mA