If I could do zero stars i would :-).
Failed after 12 hours usage
Got the unit yesterday for a Arduino project I am working - monitoring water flow and pressure. Unit worked fine last night after I installed it - reading 72psi +/- 2 psi (yes it is noisy - but I can filter sufficiently in F/W). This morning - it was reading 45psi +/-5psi - got my mechanical sprinkler pressure gauge out and had my normal 70 psi and no fluctuations. Odd said I - but thought maybe I had a loose connection or such - but nothing manifested. So went with it planning to re-calibrate it later. Well 4 hours later it is showing 112psi (5v). It is jammed solid at that value - no amount of playing - re-powering - or such recovered it. In short - it was dead. Or is that dead-short to +5 - Haha.

Anyway - a large disappointment. And from the reviews - this does seems to be a common failure. Given it was running off the Arduino 5v regulator and all the other items are happy - I must assume that it has just failed and is obviously a poor quality/design.

These could be the perfect pressure sensor for home automation projects. However, I experienced a high failure rate. I bought 3 of the 100 psi models. 2 of them failed within one week. One reads 0 volts all of the time, the other one swings wildly from 0 to 5 volts. The 3rd one works fine.

I was feeding them 4.67 Volts for power, and they were not miswired. All worked fine when tested on the bench, but when installed in an irrigation pipe they failed. Also, I used Omege PS-8E pressure gauge snubbers to protect the sensors from sudden pressure changes. The sensors should last years in this type of installation.

Update:

This unit failed after a week of operation as a water pressure transducer with pressures never exceeding 20 PSI. I cut it open to perform a post-mortem and discovered that there is no barrier between the media being measured and the circuit board (see photos). As a result, you can clearly observe where the water corroded the leads on the IC package and caused it to fail. Cheap junk. If you plan on using it to measure water pressure, don't purchase this item despite its claims.

This 30 PSI sensor performs as predicted. The voltage output is very linear, as I have tested it against a known pressure source (see attached graph). I am very pleased with the rugged nature and ease of use. The primary use is to monitor my pool plumbing pressure and I will update this review in the future, based on its performance.

Inexpensive and works. I'm using two of these to monitor fuel and oil pressure in my RX-8. I also have two others (different MFR label but otherwise identical) in my custom-built rotary compression tester. I'm using an arduino and 20x4 LCD display to process and display the data.

I hooked them up to a bike tire pump and they were within a few % of the reading on the pump gauge. You probably don't want to use these on systems requiring extreme accuracy but they work well enough for my needs.

No idea about longevity in harsh environments yet but I'll report back if they fail.

Worked exactly as it should. I will give you equations and values I found to use if you are into using Arduino....etc. If you are designing a wireless pressure sensor circuit. Using XBEE modules might be a great answer like it was for me. XBEE module analog inputs have 1023 of resolution from 0 - 1.2 volts. Since the pressure transducer outputs 0.5 - 4.5 you will need a voltage divider on the analog input of the XBEE so that at the max it will not exceed 1.2 volts. The XBEE can handle up to 3.3 volts on pin but anything after 1.2 it will ignore and just call it as 1023 value. I used two resistors. R1= 1.5K (R1 is on the high side) and R2 =4750 ohms (R2 on the GND side). So in your code, find the hex value of the input on the analog pin that you are using to find voltage on the analog pin. PinVoltage = (HexValue * 0.001173). Then [(PinVoltage / 0.24) - 0.5 volt] = Voltage output of transducer. To find PSI> PSI = (Voltage output of transducer / 0.133) Surprisingly, the values were right on target when I tested it using a pipe connected to the transducer, air compressor with pressure meter gauge. It was extremely linear and I tested it from 1 PSI to 30. Awesome little transducer! I will be transmitting the readings to a website with my design.