The deltasonic® ultrasonic flowmeters from pvt technology GmbH are increasingly being used to measure the flow of liquids. In addition to the very high precision and the simple installation, the devices of the deltasonic® series impress with an attractive price-performance ratio as well as a high processing quality. The fields of application range from feed water quantities to heat and cold quantity measurements to flow measurements for drinking water (all hygienic requirements are fulfilled).
Principle of operation
Our ultrasonic flowmeters work according to the transit time difference method. In this method, ultrasonic pulses are transmitted through the medium in and against the direction of flow. A sound wave propagates faster in the flow direction of the measuring medium than in the opposite direction. The transit time difference is thus proportional to the mean flow velocity. The average flow velocity multiplied by the pipe cross-section gives the flow volume per time unit.
The flow velocity is calculated according to the following equation:
- v = average flow velocity
- L = length of the ultrasound path
- α = Angle of the ultrasonic signal to the flow
- T1 = transit time of the ultrasonic signal with the flow
- T2 = transit time of the ultrasonic signal against the flow
Advantages of the measuring principle of the deltasonic® series
- no pressure losses because of free pipe cross-sections
- very low maintenance or servicing costs, as there are no moving parts
- long service life, as no abrasion or corrosion due to the measuring medium
- simple and cost-effective installation without interruption of operation
- all hygienic requirements are met, as no product contact through clamp-on sensors
- independent of media properties such as pressure, temperature, conductivity, viscosity, etc.
- no leakage risk
Specific advantages of the deltasonic® type WM - stationary
- Unusually high accuracy of +/- 0.5 % of the read value at a flow velocity of 0.3 to 12 m/s (SI test bench certified accuracy = +/- 0.28 % of the read value).
- Special innovation of our deltasonic® series: the patented PicoFly quantum time transit technology. By the use of two-dimensional space-time intersections as time scale an ultrasonic transit time almost without dead zone is reached, in the precision time range of less than one picosecond ~ 100 Ms.
- The deltasonic® series is highly accurate and largely insensitive to air bubbles and suspended solids.
- Fewer hardware components due to state-of-the-art microelectronics in the low-voltage range. This results in maximum performance and reliability with minimum power consumption.
- Ultrasonic sensors up to 150 °C
- Switching to the various displays is done via the Touch Keys on the front panel.
- Operation of all keys via capacitive touch buttons with unlimited service life.
- Due to the clear, user-friendly menu selection via the front keys, our deltasonic® series is very easy and extremely convenient to operate. Only a few logical steps are required for commissioning in minutes.
Technical data of the deltasonic® type WM - stationary
- Measuring principle: digital ultrasonic flow measurement according to the transit time principle
- Installation type: Wall mounting
- Nominal sizes: from (15 - 20 mm*) 25 to 6,000 mm
- Temperatures: - 20 °C to + 150 °C
- Accuracy: +/- 0.5 % at 0.3 to 12 m/s (positive/negative)
- Repeatability: 0.15%.
- Digital display: 20 x 2 alphanumeric with backlighting
- Keyboard: 4 x 4 touch keys
- Memory card: IG SD high memory data logging (512 days)
- Outputs: 4 - 20 mA 750 Ω, OCT pulse 0 - 10 KHz, relay
- Communication: RS232/RS485/Modbus
- Power supply: 90 - 250 VAC 48 - 63 Hz or 10 to 36 VDC
- Housing: Injection moulded aluminium, lacquered
- Protection class: IP 68
*For nominal widths from 15 to 20 mm, there are restrictions in accuracy due to insufficient running time
