PX880-300GI Industrial, Intrinsically Safe Press. Transmitters

 

Designed for stable performance in the toughest environments, with 316 SS welded construction, PX880 transmitters are ideal for use with corrosive media and in hazardous environments.

 

Both models have FM and CSA Explosion Proof and CSA Intrinsically Safe approvals and meet NACE standards for offshore applications (The PX880-150WCGI, 0-75 to 0-150 inches of water range does not have FM approval, only CSA Intrinsically Safe approval). With the cover retained by a stainless steel chain and no internal jumpers for span turndown, losses due to misplaced or dropped parts are eliminated.

 

The small size and light weight of both models eliminate any complicated mounting hardware or mechanical supports, which reduces installation time substantially. The integral junction box permits simple field wiring without the need for additional hardware, and adds to the speed and ease of installation.

 

OPERATION

The heart of the PX880 pressure transmitter is a silicon piezoresistive sensing chip. This miniature microetched semiconductor gives a voltage output proportional to the applied pressure. The chip is isolated from the process media by a stainless steel diaphragm. Silicone oil is used to transmit the process pressure to the sensor.

 

An amplifier PCB enclosed in a sealed chamber is used to convert the millivolt signal from the sensor to a calibrated 4 to 20 mA transmitter output. Feed-throughs for EMI and RF protection are used between the amplifier board and the terminal housing.

 

Each transmitter is tested over both pressure and temperature ranges. A compensator circuit is used to bring the output of the sensor into specification. After compensation, every transmitter is tested a second time for pressure and temperature effects to ensure that it meets performance specifications. The transmitters are calibrated to the upper ranges listed in the order box, but end users can recalibrate them to different ranges. Recalibration is done via 3 screw potentiometers inside the transmitter’s head. Recalibrating to any range between the 2 listed for a particular sensor can be accomplished with a known pressure source.

 

The PX881 is flush diaphragm pressure transmitter, designed to mount flush against process media and to prevent any media particles from collecting at the diaphragm.