PX26

Supported Applications

The Omega PX26 Series consists of wet/wet differential and gage pressure sensors designed for board-mounted installations. These four-active piezoresistive bridge devices produce an output voltage proportional to applied pressure, featuring a unique conductive seal between the silicon diaphragm and plastic housing that allows both sides of the sensor to handle liquids.

Documented compatible media include oils, lacquer thinner, hydraulic fluid, most petroleum products, water, salt water, and many other liquids. The series is not recommended for use with freons. Input media must be limited to those which will not attack polyethimide (polyester), silicon, or fluorosilicone.

Operating Conditions & Performance

The PX26 Series operates within an ambient temperature range of -40 to 185°F (-40° to 85°C) and a compensated temperature range of 32° to 122°F (0° to 50°C). Storage temperatures are rated from -67° to 212°F (-55° to 100°C).

Performance specifications include:

• Accuracy/Linearity: ±0.25% FS BFSL typical (±1% maximum) for P2 > P1.
• Hysteresis and Repeatability: 0.2% FS.
• Response Time: 1 ms.
• Stability: 0.5% FS over one year.

The series is qualified to withstand shock up to 150 G and vibration at 2kHz @ 20 G sine. Proof pressure ratings vary by range: 20 PSI for ≤5 PSI ranges, 45 PSI for the 15 PSI range, 60 PSI for the 30 PSI range, and 200 PSI for the 100 PSI range.

Configuration Options

The PX26 Series is available in Gage (reference to atmospheric pressure) and Differential (two independent pressure sources) configurations. Measurement ranges span from low-pressure applications up to high differential pressures:

• Gage Ranges: 0-1 PSIG, 0-5 PSIG, 0-15 PSIG, 0-30 PSIG, 0-100 PSIG, and 0-250 PSIG.
• Differential Ranges: ±1 PSID, ±5 PSID, ±15 PSID, ±30 PSID, ±100 PSID, and ±250 PSID.

Electrical specifications include an excitation voltage of 10 Vdc (max 16 Vdc @ 2 mA). Output signals vary by range: 16.7 mV for the 1 PSI range, 50 mV for the 5 PSI range, and 100 mV for ranges greater than 5 PSI.

Physical dimensions are compact at 21.8 mm (0.86 in) length, with a diameter of 6.4 mm (0.25 in). The pressure port features a 0.2" dia. and 0.25" collar dia. Wetted parts consist of polyethimide, silicon, and fluorosilicone.

Accessories

• CX136-4: 4-pin mating connector (sold separately).
• TX4-100: 4-conductor copper wire, 30.5 m (100').
• TY316-100: Flexible plastic tubing, 30.5 m (100').

Key Product Differences

The series distinguishes between Gage and Differential models via the model number suffix: "GV" denotes a gage sensor referenced to atmospheric pressure, while "DV" indicates a differential sensor capable of measuring two independent pressure sources. The PX26 construction utilizes silicon sensors with a larger diaphragm than traditional gold wire silicon sensors, intended for increased long-term stability.

Model numbers follow the format PX26--. For example, PX26-030DV represents a bi-directional range of ±30 psid. The electrical connection utilizes a 4-pin mating connector (CX136-4) with Pin 1 as +EXC (notched), Pin 2 as +OUT, Pin 3 as -EXC, and Pin 4 as -OUT.

Users are advised to install pressure snubbers or surge chambers to avoid damage from fluid hammer and surges, which can occur when liquid flow is suddenly stopped or begun. Symptoms of such damage include large zero offsets, constant output regardless of pressure, or no output at all.