Federal Interagency Sedimentation Project
US VTP-99 VERTICAL TRANSIT RATE PACER
HIF/FISP Part # 4110032
*Pricing may change due to manufacturer reordering,
please call the HIF at (800) 382-0634 for final pricing and
The US VTP-99 vertical transit rate pacer is a commercially manufactured electronic programmable metronome. It provides an audible time-interval reference for pacing the lowering and raising of a suspended-sediment sampler when collecting depth-integrated samples. The audible signal eliminates the use of a stopwatch.
The uniformity of the vertical speed of a sampler directly affects the accuracy of depth-integrated samples. The pacer makes uniform vertical rates possible and therefore helps to ensure an accurate flow-weighted sample. Any operator may reproduce a given vertical rate at any time and at any location. Reproducibility is particularly important when collecting samples using the ETR (equal-transit-rate) method.
The pacer may be used with handheld samplers as well as mechanically hoisted samplers. The small size permits carrying the device in a shirt pocket. The tone is audible for several feet so that in a quiet environment a headphone is not required. The US VTP-99 has a miniature phone type monaural headphone jack. Headphones are not supplied.