The Mass Flow Computer P7028 is used in conjunction with Cussons Laminar Flow Meters (LFM) for the measurement of air flow in automotive applications.
The instrument uses two precision pressure transducers to measure the differential pressure across the laminar flow element (LFE), and absolute pressure upon discharge from the LFE, and a platinum resistance thermometer to measure the air temperature.
From these measurements a 16 bit microprocessor calculates:-
The volume flow rate at the prevailing temperature and pressure
The volume flow rate corrected to standard conditions (Temperature 15ºC; pressure 1013.08 mbar)
The mass flow rate
The microprocessor automatically corrects the flow rates to take account of changes in the viscosity of air with varying temperature.
The three primary measurements and the three calculated flow rates may be independently displayed in engineering units on a 4 digit LED display by means of six push button selection switches mounted on the instrument front panel.
An analogue output is provided to enable logging of either the mass flow rate or the corrected volume flow rate.
The instrument is designed for use with either one or two LFMs with the latter option enabling the following application to be achieved.
Where the air flow to be measured exceeds the range of available LFMs, a system using 2 LFMs in parallel, as illustrated in Fig. 1, can be used to solve the problem.
Where optimum resolution is required over a wide range of air flow rates, a system using selected LFMs in parallel, as illustrated by Fig. 2, can be used to produce an exceptionally large turn-down ratio. The instrument
provides for either manual or automatic change-over between the two LFMs.
For large engine applications involving two separate air intakes, individual LFMs can be used for each intake as illustrated by Fig. 3. Similarly, one P7028 instrument can be used in conjunction with two LFMs operating in adjacent test cells.
An LFM Change-over Module is available as an accessory for use in dual LFM applications.

Standard 3u 19" rack for mounting in 19" cabinet. Optionalenclosure P7030 available for free standing use.
FRONT PANEL
Fitted with:-
illuminated push-button switches for display of measured variables; differential pressure (mmH2O), absolute exit pressure (mbar), and exit temperature.
illuminated push-button switches for display of computed results: volume flow rate (litres/sec), volume flow rate corrected to standard conditions (litres/sec), and mass flow rate (g/s).
Note: The standard conditions referred to are pressure of 1 atmosphere (1013.08 mbar) and temperature of 15ºC.
Four digit seven segment numeric display, 14.2 mm high. Minus sign, segmented display of engineering units. Updated every 250ms approximately.
Autoranging where appropriate.
illuminated push-button switches for selection of LFM.
Illuminated push-button switch for power on/off. 

DISPLAY                   FULL SCALE         RESOLUTION
Differential Pressure     0-300 mm H2O      0.5 mm
Absolute Pressure         0-3500 mbar        2 mbar
Temperature               0-100ºC            0.1ºC

Standard 3u 19" rack for mounting in 19" cabinet. Optionalenclosure P7030 available for free standing use. 
FRONT PANEL 
Fitted with:- 
illuminated push-button switches for display of measured variables; differential pressure (mmH2O), absolute exit pressure (mbar), and exit temperature. 
illuminated push-button switches for display of computed results: volume flow rate (litres/sec), volume flow rate corrected to standard conditions (litres/sec), and mass flow rate (g/s). 
Note: The standard conditions referred to are pressure of 1 atmosphere (1013.08 mbar) and temperature of 15ºC. 
Four digit seven segment numeric display, 14.2 mm high. Minus sign, segmented display of engineering units. Updated every 250ms approximately. 
Autoranging where appropriate. 
illuminated push-button switches for selection of LFM. 
Illuminated push-button switch for power on/off. 

DISPLAY                   FULL SCALE         RESOLUTION 
Differential Pressure     0-300 mm H2O      0.5 mm 
Absolute Pressure         0-3500 mbar        2 mbar 
Temperature               0-100ºC            0.1ºC