Pressure Sensors Frequently Asked Questions
Use "Ctrl-F" to search for specific words in this FAQ.
Question:
Can I use a ProSense transmitter with your AC drives?
Answer
Yes, all of our AC drives will accept the 0-10v or 4-20mA signals from the ProSense transmitters, but for the GS series, you must use an external DC power supply, typically 24vdc because the 0-10v transmitters need a minimum of 16 volts for their supply.The power supplies on the GS series are only to supply a potentiometer and are extremely small.
The Hitachi SJ300's actually have a 100 mA supply, and will power the transmitters without need of an external supply.
FAQ ID: 1119
Question:
What are the wiring colors/pinouts for the transmitters?
Answer
For the PTD25-10 models, pin 1 is DC+(Brown), pin 2 is the Signal Output(White), and pin 3 is DC-(Blue).
For the PTD25-20 models, pin 1 is DC+(Brown) and pin 2 is the Signal Output (White). The DC- connection is made at the device (for GS drives, it's CM(GS1) or ACM (GS2 and GS3) terminal).
FAQ ID: 1120
Question:
Can I use the ProSense sensors with gases?
Answer
The PTD25(transmitter) models can only be used for gases up to 363 psi. They have an 0-ring that can deteriote with sudden depressurization, and can cause the sensor to fail.
For the PSD25(switch) models, they are rated for gas or liquid up to their pressure rating, so long as the chemical compatability is correct.
Here are some images of what will happen to the O-ring if sudden depressurization occurs:
http://support.automationdirect.com/faq/images/gasket1.png
http://support.automationdirect.com/faq/images/gasket2.png
For the SPT25 pressure sensor, regarding use in oxygen service: while the sensor is compatible for use with oxygen as a process fluid, the supplier has indicated this instrument is not "Cleaned for Oxygen Service". For those industrial processes (like cryogenic air separation) that require all instrument be cleaned for O2 service, this sensor is not recommended.
FAQ ID: 1121
Question:
What types of pressure transmitters/switches do we carry?
Answer
No "Absolute" or "Differential" sensors.
Ours are all "gauge-based", this means that "0" represents sea-level.
Our vacuum sensor can only read down to -14.5 psi ( about 29.9 inches of Hg or mercury).
Only 1/4" male NPT thread. No others threads available.
Body is Stainless Steel, so is resistant to most common chemicals. Check chart for exact compatability.
Accuracy is +/- 0.75%.
3-year warranty.
M12 connector ( same as most 12 mm (and up) prox switches.
FAQ ID: 1148
Question:
What are the power requirements?
Answer
Our PTD25-10-xxxx ( 0-10 v) require a 16-32 vdc power supply.
Our PTD25-20-xxxx ( 4-20 mA) require a 10-30 vdc power supply.
Our PSD25-xx-xxxx switches can use 10-32 vdc power supply.
FAQ ID: 1149
Question:
What are the pressure ranges?
Answer
Transmitters:
PTD25-xx-xxxx ranges:
-14.5 - 0 psi (vacuum: high signal level at high vacuum)
0-100" WC (approx 3.6 psi)
0-15 psi
0-30 psi
0-100 psi
0-200 psi
0-500 psi
0-1000 psi
0-3000 psi
Switches
PSD25-xx-xxxx ranges:
-14.5 - 0 psi(vacuum: high signal level at high vacuum)
7.5-145 psi
75-1450 psi
290-5800 psi
FAQ ID: 1150
Question:
How do I adjust the PSD series sensors?
Answer
The SET and RESET adjustments (Rings) are mechanically interlocked to prevent setting less than the minimum offset required by the sensor. You cannot use the same pressure setting for the SET and RESET. There must be some hysteresis (offset) to the settings.
All the directions assume you are looking at the cable end of the sensor.
- Unlock the sensor adjustments (top most ring). The unlock symbol will line up with center arrow when unlocked.
- Rotate the LOCK ring clockwise until it stops.
- Adjust the SET point (2nd ring from top) to it's lowest setting.
- Rotate the SET ring counter-clockwise until it stops.
- The RESET ring will start moving at some point to maintain the mimimum offset.
- Adjust the RESET point (3rd ring from top) to the desired reset point. This is the pressure at which the sensor will turn off after being turned on. This has to be offset from the SET to prevent chattering/rapid cycling.
- Rotate the RESET ring clockwise to the desired reset point. - The SET will move also to maintain the offset.
- Check the setting of the SET ring. You cannot adjust the SET point lower than the reset so the reset may move.
- If this needs to be adjusted, the RESET will be affected to maintain the offset.
FAQ ID: 1187
Question:
What is the resolution of the ProSense pressure transmitters?
Answer
For the PTD25 pressure transmitters, they have an 11 bit resolution. If you divide the total range of the transmitter by 2048 this will show what pressure change is required to see a corresponding change in the analog output. For example, for the 0-100PSI transducer, 100 / 2048 = 0.05, so the transducer will change its output for every 0.05PSI pressure change.
The SPT pressure sensors are an analog type and don't use a DAC converter.
FAQ ID: 1199
Question:
Is there a limit to the amount of vacuum a PTD25 series sensor can be subjected to?
Answer
You can pull a full vacuum (-15psi of external pressure as per the ASME) without damaging the product; of course the analog output will go out range.
FAQ ID: 1366
Question:
Can you provide a "Certificate of Calibration" or similar?
Answer
We're sorry, none of our sensors have that available. This also applies to our temperature sensors.
FAQ ID: 1377