Your instructions are crap. Omega is a distributor that puts its name on a bunch of stiff but has terrible support. The manufacturers website shows something much easier.

Connect red and black wires to your DC power supply.

Connect white and green wires to your AINx and SGND connections of your meter.

The unshielded wire can be left unconnected for now.



http://cecomp.com/pdf_old/cecomp_dpg1000dar.pdf

 

Your instructions are crap. Omega is a distributor that puts its name on a bunch of stiff but has terrible support. The manufacturers website shows something much easier.

Connect red and black wires to your DC power supply.

Connect white and green wires to your AINx and SGND connections of your meter.

The unshielded wire can be left unconnected for now.
View attachment 116408


http://cecomp.com/pdf_old/cecomp_dpg1000dar.pdf

Thanks for the reference!

 

Thanks for the reference!

You may need a 240 ohms of resistance across green and white wires.

 

Yes I believe I do have a 240 ohm resistors across. I have the 2x120 ohms resistor in series in my circuit. and is there a certain reason why i have to have a 240 ohm resistor?

I have a 1.6 voltage reading from the white and green wires, however no current. I have plugged wires into labjack as shown in the picture.
Can you guys point me in the right directions of what to do with the other 6
wires.

 

Make sure your wires are not shorting out. The photo near the Q of a laptop keyboard looks like some wires are touching. Also, move the wires near the resistor. Looks like a mess.

Also, your camera is quite good, we can zoom in. Back up so we can see where the wires are coming from.

 

Yes I do need to clean up some, it is a mess. It's kinda my first time dealing with this. I took hopefully a better photo of all the connections and where they are. The red and black wires with the alligator clips are from the power supply, and then the right side is from the sensor.

Can I use any combinations of resistors to make the output of the signal between the range of what labjack can handle? I still don't understand the specifics of why it has to be 240 ohms.

 

The LabJack can read voltages from 0 to 5 volts.

According to Ohms law, voltage = resistance X amps

So, 0.02 Amps X 240 ohms yields just under 5 volts. (0.02 Amps = 20 mA).

Any thing less, down to 0 will give less. Your sensor outputs 4 to 20 mA to get almost the full 5V range.

 

Ok, on the LabJack, only connect
** Green wire from sensor to GND
** white wire to AIN0

No other wires except USB cable.

DO NOT CONNECT ANTHING TO Vs

 

OK thank you!! so much help... I think I have one more questions.. I have 2 pressure gauges, the one I had set up was for the outlet of the evaporator coil. I did the same circuit on the breadboard for a pressure gauge measuring the inlet pressure of the Condensing coil, however its giving me a different out?

Why isn't the output voltage the same? It's giving me about 2 more volts higher.

 

OK thank you!! so much help... I think I have one more questions.. I have 2 pressure gauges, the one I had set up was for the outlet of the evaporator coil. I did the same circuit on the breadboard for a pressure gauge measuring the inlet pressure of the Condensing coil, however its giving me a different out?

Why isn't the output voltage the same?

There is a "Zero" set screw on top of the gauge. Turn that until your output reads zero when pressure is zero.
THEN, apply a known pressure and set the SPAN knob until you get the desired reading.

 

I turning the "Zero" screw, on the gauge pressure display, the number is going down, but the output voltage is not changing.

 

I turning the "Zero" screw, on the gauge pressure display, the number is going down, but the output voltage is not changing.

Call/email the supplier to see what is possible. Maybe you have to zero the software and the zero on the gauge only zeros the value on the display (like you said).

 

What is the FULL model number ?

I believe he has this one...

http://cecomp.com/pdf_old/cecomp_dpg1000dar.pdf

 

I believe he has this one...

http://cecomp.com/pdf_old/cecomp_dpg1000dar.pdf

Which doesn't answer the "full" model number question you had, @Robert Murphy !

 

From reading that doc it appears the output could either be 4 - 20 ma or 0 -2V.

I do feel if the OP fully read the doc I linked to he may gain a better understanding of operation.

Yes, I see from the datasheet that I linked there are multiple ranges available and those would lead to different outputs for a given pressure. And the 0 to 2 vs 4 to 20 mA issue will change things.

Here is the decoder ring...

 

I have two gauges:
DPG1000 DAR 300 G 1N
DPG1000 DAR 500 G 1N

I seen on the OMEGA Specs sheet, I have the DAR which outputs the 4-20mA outputs.

From what I think, correct me if I'm wrong, the sensor is outputting a signal in 4-20mA (depending on the voltage supplied), then we took that signal and got a voltage reading off of that from the circuit that was made, so that LABJACK-U3 can read it. Would I think find something to convert that voltage reading into a pressure ?

 

I have a problem, when the system is not on, one of the gauge is giving me a different output voltage, however its on the same circuit as the other gauge?

 

I have a problem, when the system is not on, one of the gauge is giving me a different output voltage, however its on the same circuit as the other gauge?

You can't rely in the output of a sensor when it is not powered. If you want to use it, give it power. If you don't care what the output value is, turn it off but you're not saving much power so you may as well leave it on.

 

I'm sorry, i probably how i worded it. So the the sensor is on. The pressure of both gauges is the same, its around 110psi when the System is on stand-by. This is where I am getting the 2 volts difference between the gauge output.

When we turn the system on, I can't even plug the output into the labjack because the voltage is so high.

 

I'm sorry, i probably how i worded it. So the the sensor is on. The pressure of both gauges is the same, its around 110psi when the System is on stand-by. This is where I am getting the 2 volts difference between the gauge output.

When we turn the system on, I can't even plug the output into the labjack because the voltage is so high.

If it us under 5 volts, you should be good.

Also, one meter has a full scale of 500 and one has full scale of 300 units so any non-zero input will have different value.