NE74 Differential Pressure Sensors from Celsum Technologies

Pressure ranges ±150mbar to ±100 bars (2 to 1500 psi)
Over-range up to 10 x full scale
400 bar (5800 psi) line pressure for differential mode
Wet/Wet Differential, Absolute versions
Variable Reluctance stability & reliability
Insensitive to shock & vibration
Wide operating temperature range (-45 to +200°C)
All-welded stainless steel construction

The NE74 Series was initially developed for oil and gas exploration applications, but has also many other uses.

Typical applications include differential pressure measurement in down-hole installations with a very high over-range capacity, and depth measurement in high temperature and high vibration applications.

The NE74 pressure sensor uses the variable reluctance technique and consists essentially of a diaphragm made from a magnetic material mounted centrally between two end pieces, Each end piece consists of a fixed coil potted in high temperature resin and sealed by means of a welded stainless steel shim to completely isolate the coil from the pressure medium. The diaphragm is machined from a solid forged section and electron-beam welded to the end pieces. This produces an extremely rugged assembly with superb environmental characteristics and very good reliability figures (100,000 hours MTBF).

On the application of a differential pressure, the diaphragm is deflected, resulting in the inductance of one coil and a decrease in the other. This is detected by simple AC circuitry.

Technical Specifications

Full Scale Ranges:

140, 350, 700 mbar
1, 2, 3.5, 7, 10, 20, 30, 70, 100 bar
2, 5, 10, 15, 30, 50, 100, 150, 300, 500, 1000, 1500 psi

Over-Range:

10 x Full Scale

Line Pressure in Differential Mode:

<400 bar (5800 psi)

Performance:

Linearity:                    ±0.25% of Full Scale
Hysteresis:                ±0.15% of Full Scale
Repeatability:            ±0.1% of Full Scale

Electrical Characteristics:

Supply Voltage:         5V RMS 1kHz to 10kHz (optimum 3kHz to 4kHz)
Sensitivity:                 25mV/V ±50% at 3kHz
Output Impedence:  150 Ohms, >16mH
Insulation:                   > 100 Megohms at 250V

Mechanical Characteristics:

Electric Connections:      Solder pins
Pressure Connections:   Manifold mounting using O-ring seals
                                            Option of mounting plate with threaded
                                            pressure ports.
Wetted Materials:            17-4PH Stainless Steel
                                            Teflon® O-ring
Weight:                              100 grammes approx
Dimensions:                      Nom 27 x 27 x 30 mm Standard
                                            Nom 45 x 33 x46 mm Threaded Port Option

Environmental Characteristics:

G Sensitivity:                   <0.15P^2/3% per G
                                           (where P is pressure range of capsule)
Mechanical Shock:         1000g for 1ms in each mutually perpendicular                                            axis will not affect the capsule

Temperature Coefficients:

Sensitivity:                      <0.05% of reading/°C nominal
Zero Offset:                    <0.03% of Full Scale / °C nominal
Operating Range:          -45 to +200°C
Storage & survival:       -60 to +220°C

ORDERING CODES:

NE74/A/BBBB/C/D/EE

where

A = Temperature Range: -45 to +200°C = H

BBBB = Pressure Range

C = Reference: True Differential = TD Absolute = A

D = Units: bar or mbar = B psi = P

E = Pressure Fitting* (Optional)

AA	1/8 BSP Male	HH	7/16 UNF3A Female
BB	1/8 BSP Female	SS	M8x1x4H Female
CC	5/16 UNF3A Male	TT	M8x1x4H Male
DD	5/16 UNF3A Female	UU	M10x1x4H Female
EE	3/8 UNF3A Male	VV	M10x1x4H Male
FF	3/8 UNF3A Female	WW	M12x1x4H Female
GG	7/16 UNF3A Male	XX	M12x1x4H Male

*NB Male = male 60° cone seat; female = 60°cone seat
All threads are male/external

For applications requiring specifications outside those listed,
please contact us.