tekFab + tekProbe – Averaging Pitot Flow Sensors

The Tekflo tekFab DP02 Series brings the most advanced all-digital pressure (dp) sensing to Tekflo’s insertion tekProbe PR3 multivariable averaging Pitot flow sensors. This ideal Multivariable system is used for liquids, mass flow or density corrected volumetric flow measurement of gases, saturated or superheated steam in pipes and ducts 50 to 3000mm (2″ – 120″).

The flow computation is entirely digitally and accomplished within the tekFab DP02 DP Cell. It is based on classical Bernoulli Theory, which defines a true static pressure input. Only the Tekflo PR3 averaging Pitot produces such a noise free true static pressure. Other industrial Pitot types measure either a suction pressure, or an attempt at static pressure measured on the side of a costly profiled tube in the pipe line. Both these types result in a noisy, erroneous static pressure, resulting in erroneous flow measurement.

Besides all digital square root extraction and mass flow computation, the Tekflo tekFab DP02 series uniquely accomplishes all- digital sensing. It embodies two nanomolecular crystal silicon resonators, protected behind silicon oil filled diaphragms. The resonators are caused to vibrate at their natural frequencies. These are shown by 2 elongated H shapes in the diagram below. The tekProbe produces a noise free dp across the H resonators. One vibrates in a +ve compression mode, while the other vibrates in a -ve tensional mode. The resultant dp signal, (fc – ft) in the diagram, together with tekProbe’s noise free true static pressure input to the dp transmitter’s computer, (fc + ft) in the diagram, provides unmatched total system mass flow accuracy, repeatability, and resolution, with virtually zero hysteresis. tekFab DP02 Series is internationally certified for use in explosive atmosphere.

Being entirely the tekFab DP02 reduces the combined errors of temperature, overpressure, hysteresis, square root extraction, computation, static span and zero span to insignificance

• dp accuracy : .+/- 0.04% of span traceable to USA NIST
• static pressure : accuracy +/- 0.1% of span
• stability : .+/- 0.1% of URL over 10 years
• ambient temp : effects +/- 0.055% of dp URL per 28°C (50°F)
• dp pressure range : 0 – 10 to 1000mm wg, 0 – 0.4″ to 40″ wg
• max static pressure : 169 barg (2300 psig)
• non isolated output : 4 x 4 – 20mA 2-wire for flow rate, dp, static pressure, temp, 0- 10kHz scaleable pulse
• HART supply : 10.5 – 42Vdc for general & flameproof application

Downloads

tekFab DP02 + tekProbe Shortform Leaflet

tekFab DP02 + tekProbe Specifications and Technical Data Sheet

The Tekflo tekFab DP04 Series brings uncompromised low cost, but with the most advanced nanotechnology capactive reactance differential pressure (dp) sensing to Tekflo’s insertion tekProbe PR3 averaging Pitot flow sensors. This low cost version complements the tekFab Multivariable system. However, this system is used for simplified volumetric flow measurement of liquids, gases, saturated or supersaturated steam, with a fixed mean density, in pipes and ducts 100 to 3000mm (4″ – 120″).

The flow computation, displayed digitally on the tekFab DP04, is based on classical Bernoulli Theory, which defines a true static pressure input. Only the tekflo PR3 averaging Pitot produces such a noise free true static pressure. Other industrial Pitot types measure either a suction pressure, or an attempt at static pressure measured on the side of a costly profiled tube in the pipe line. Both types result in a noisy, erroneous static pressure, emanating in erroneous flow sensing.

The Tekflo tekFab DP04 DP Cell series uniquely accomplises the most long-term accurate sensing by embodiment of two nano- molecular crytalline silicon filled chambers, which construct virtually a solid state capacitive reactance sensor. The sensor contains two high natural frequency diaphragms, which sense the +ve and -ve differential pressure produced by the tekProbe. The high natural frequency and virtual solid state tekFab construction ensures virtual insensitivity to normal plant shock and vibration even at low range dp.

The tekProbe produces a noise free true static pressure and impact pressure to provide unmatched total system mass flow accuracy, repeatibility and resolution, with virtually zero hysteresis.

Features

• Unique dp sensing chamber provides 500% of upper range limit static pressure overload protection
• Sensing chamber incorporates Czochralski nanotechnology mono- crystalline silicone. Nano molecules (down to 0.000000001m) provide the ultimate fluidic long term stability and strength, which is transferred to the tekFab measurement system
• Virtual solid state sensing chamber provides high insensitivity to shock and vibration, even with low dp ranges
• dp accuracy : .+/- 0.25% of span traceable to USA NIST
• static press : accuracy +/- 0.1% of span
• stability : .+/- 0.1% of URL over 6 months
• amb.temp : effects +/- 0.2% of dp span per 56°C (135°f)
• external temp : norm temp -30°C to +93°C (-22°F to +220°F)
• max static : pressure 10barg (145psig), 40barg(590psig)
• dprange1 : 0 to 10mm to 150mm wg (0 – 0.4″ to 6″wg)
• dprange2 : 0 to 40mm to 400mm wg (0 – 1.5″ to 15″ wg)
• dprange3 : 0 to 60mm to 610mm wg (0 – 2.5″ to 25″ wg)
• vibration eff : 0.05%of max range/g for frequencies <200Hz
• 2-wire o/p : 4 -20mA, 12 – 45 Vdc, default with square root extraction for flow measurement
• Protocol : HART superimposed on 4 -20mA signal
• 4-wire o/p : 110/220 Vac, 50/60Hz with 0 – 10mA
• Display : 5-digit LED or LCD numerical display
  A bargraph is configurable to display up to 4 variables
• Certification : Ex ia IIC T3 – T6 / Ex d II C T4 – T6
• Protection : IP65 and NEMA 4X

Downloads

tekFab DP04 + tekProbe Shortform Leaflet

tekFab DP04 + tekProbe Specifications and Technical Data Sheet