Liquid Controls

Slipstream™ Densitometer

The Slipstream™ Density Measurement System (SDMS) is an add-on density measurement system for the Liquid Controls and Avery-Hardoll Flowmeters. The SDMS re-routes fuel from the outlet side of the meter through the densitometer and back into the outlet side of the meter.

The Densitometer measures the density of the fuel throughout the duration of a fueling and sends real-time density measurements to the LectroCount® LCR 600 electronic or MASTERLOAD III™ registers.

  • The registers display the real-time fuel density during fueling.
  • The average density and the total weight of fueling are printed on the fueling ticket.

Slipstream™ Densitometer

Fuel density measurement for fuel mass reporting accuracy

Provides real-time measurements with liquid densities between 0.6 to 1.3 g/cc on:

  • Mass
  • Density
  • Concentration
  • Temperature
  • Viscosity


Optimized Fuel Loading:  Provides ability to optimize fuel loading for airline flight dispatching operations.

Inventory Control:  Enables true fuel measurement and custody transfer data for improved fuel management and inventory control.

Saves Fuel Shrinkage (loss discrepancies):  Provides accurate fuel mass reporting to eliminate fuel shrinkage.

Measurement Accuracy:  Provides more accurate measurements of densities of fuel loaded onboard and provides improved accuracy in reporting carbon dioxide (CO2) emissions per flight under the European Union (EU) Environmental Trading Scheme (ETS) regulatory requirements. 

Automatic Reporting:  Automated reporting of density / mass data electronically to the fueling operator eliminates errors caused by manual measurements and manual data input.

IATA Technical Fuel Group concluded that reducing fueling overage by an average of 436 pounds per flight would save up to $28,000 / day (Assuming 225 flights per day). *  (See chart below)

Data provided by the IATA Technical Fuel Group (TFG), Fuel Volume versus Weight Task Force report, section 2.3.3.

Data provided by the IATA Technical Fuel Group (TFG), Fuel Volume versus Weight Task Force report, section 2.3.3.

Slipstream™ Densitometer ROI: 

IATA task force concluded that slipstream densitometers, used on refueling equipment, can have a return on investment (ROI) of about 66:1*


A density sensor adapter kit is available separately. The adapter kit allows SDMS installation at a later date without removing any piping from the system.

Slipstream™ Densitometer Adapter Kit.



  • Digital Density: 0.0001 g/cc
  • Analog Density: +/- 0.1% of full scale
  • Temperature: 0.6 °F (0.3 °C)
  • Repeatability: 0.00003 max g/cc

Max Pressure    

  • 300 psig (21.7 bar) standard

Operating Temperature    

  • -4 to 140˚F (-20 to 60 °C)

Sample Rate    

  • 100 mS

Power Supply    

  • 5 VDC, 500 mW USB or 8-30 VDC


  • 400 mW


  • (2) 4-20mA analog, optional


  • USB, standard RS-232, optional RS-485, optional


  • EX IIC, AEx, CUL, UL (Class 1 Div 1, Group