VALEPORT Model 108 MkIII Self Recording Direct Reading Current Meter

Current Meters and Open Channel Meters have been a speciality of Valeport's since the company was first formed in 1969. The company started making instruments for measuring the speed of the water in London's River Thames,  since then our product range has grown, but our expertise in current flow measurement remains.
Whichever type of instrument your require, whether it's the traditional impeller mechanism, or the high accuracy electromagnetic type, Valeport can offer a solution. Configurations are available that are suitable for use in a wide variety of applications, from hand held measurements in the smallest streams, through modelling experiments in the laboratory, to self-contained instruments for navigable rivers, estuaries, ROVs and the deep ocean.
Our impeller instruments use the simple premise of measuring the speed of rotation of a helix in the water. PTFE bearings eliminate the need for specialised lubricants and the magnetic contact closure minimises the moving parts in the system - this also allows the sensor itself to be remote from the measuring electronics (ideal in deep water applications).

The electromagnetic sensors use the Faraday Principle to measure the water speed. As a conductor (water) moves through an electromagnetic field (generated by the sensor), it generates a voltage that is measured by the sensor electrodes. Modern day signal conditioning electronics and filtering techniques allow highly accurate measurements to be made, and there is a choice of sensor shapes and sizes to suit the application. The solid state sensors and standard titanium / polyurethane construction provide excellent corrosion resistance, and depth ratings up to 5000m.
Contact our Sales team to discuss your Current Meter requirements, and decide on the right instrument for the job.

A direct reading, vector averaging current meter with surface readout unit and 200m cable. The unit can also be operated via a short lead, over an ROV umbilical. The Model has been developed to meet the needs of oceanographers, hydrographers and surveyors. Speed and Direction sensors are fitted as standard, with optional Conductivity, Temperature and Depth sensors.

Data Acquisition - The vector average is based on a 5 second period during which impeller counts are measured and a single mass compass reading is made, and the vector average is built up over the averaging period set. Averaging period is any multiple of 5 seconds, up to a maximum of 30 minutes. For the optional parameters, the sample is taken at the end of each sample period, and averaged over the averaging period. Real time display is updated at the end of each averaging period.

Technical Specification
SENSORS     
Speed     
Type    Impeller [0.27m pitch x 125mm ø]
Range    0.03 to 5.0 m/s
Accuracy    <0.15m/s, ±0.004m/s or >0.15m/s, ±1.5% reading
Resolution    0.001m/s
Direction     
Type    Flux gate compass [± 25º gimbal]
Range    0-360º
Accuracy    ± 0.25º
Resolution    0.25º
Temperature     
Type    PRT
Range    -5 to 35ºC
Accuracy    ± 0.02ºC
Resolution    0.002ºC
Conductivity     
Type    Inductive coils
Range    0.1 to 60mS/cm
Accuracy    ± 0.05 ms/cm
Resolution    0.003mS/cm
Pressure     
Type    Strain Gauge
Range    100, 200, 500 or 1000 dBar
Accuracy    ± 0.1% FS
Resolution    0.005% FS
COMMUNICATIONS     
RS232    Standard, up to 100m cable direct to PC
Digital Current Loop    Standard fit, used by 8008 CDU, this is a 2 wire method suitable for real time communications over cable lengths up to 3000m (requires an ad
SOFTWARE     
Software    Supplied with Valeport's own Windows based DataLog software, which allows the user to set up intrument sampling regime and display data.
CONTROL DISPLAY UNIT    Used in real time with Valeport's 8008 Control Dsiplay Unit (CDU). This features an LCD grpahics display of all parameters and allows full s
Power    8 x 1.5v "C" cells (also powers instrument)
Protection    IP67 (10 secs @ 0.3m)
POWER     
External    10 - 18vDC, PHYSICAL     
Depth Rating    2000m
Materials    Titanium & Acetal
Suspension    100kg