This three-wire pressure transducer pinout, drive type, and electrical specifications are unknown. It should be a typical industrial transducer. I have tried assuming it is an amplified device with a 0-5, 0-10 V output, or 4-20 mA output. No combination of wiring results in an output signal correlating to applied pressure. Edit Note: I applied 10 bar, which the Agilent 1100 HPLC system easily resolves in normal operation.
The transducer comes out of a late 1990's designed Agilent 1100 HPLC scientific pump, where it measures the output pressure up to 440 bar (6500 PSI). It is part of a pulse dampener, so I wish to keep it intact. I do not have access to the drive PCB any longer.
The markings are: Agilent Technologies Part No. 5065-9907 Revision A Date code 21/03 PA-23R / 81088 440 bar
I suspect this may be a Keller OEM transducer. Keller's currently advertised lines do not include a 23R, but they follow a similar product naming convention - PA-23R could make sense.
The transducer has three wires in a 0.100 pitch ribbon cable, so unshielded, One is black striped. It is pin 1 in the tables below.
I've monitored the drive (edited) current while powering the transducer for repetitive pulses as evidence of a microcontroller. I also monitored for pulses on the output and power fluctuations during boot time. No evidence of active electronics.
The only configuration that shows any response at all is #5 below. The output voltage decreases slightly as pressure increases. However, the output voltage depends on the supply voltage. This seems unusual if it is an amplified transducer.
Note: During each resistance check, I cycled the applied pressure between 10 bar and 1 bar (atmospheric).
The pin-to-pin resistance matrix is:
pin 1 (black) | pin 2 | pin 3 | |
---|---|---|---|
pin 1 | x | 1.52 MΩ | 13.98 MΩ |
pin 2 | 1.52 MΩ | x | 11.12 MΩ |
pin 3 | 13.94 MΩ | 11.08 MΩ | x |
The pin-to-pin voltage drop is:
pin 1 | pin 2 | pin 3 | |
---|---|---|---|
pin 1 | x | 1.64* V | open |
pin 2 | 0.73 V | x | open |
pin 3 | 1.93 V* | 1.72 V | x |
*Values decreased when attaching the meter.
Powering the transducer with a 15 VDC supply current limited to 60 mA gives this result set:
Config | pin 1 (black) | pin 2 | pin 3 | current (mA) |
---|---|---|---|---|
1 | +15 | 0 | out | 43 mA |
2 | +15 | out | 0 | 16 mA |
3 | 0 | +15 | out | 22 mA |
4 | 0 | out | +15 | 0 mA |
5 | out | +15 | 0 | 0 mA |
6 | out | 0 | +15 | 0 mA |