Using Pc-Lab 2000 SE for differential pressure and flow rate reading


#1

I am using PCS10/K8o47 with Pc-Lab 2000 SE to capture data for differential pressure and flow rate measurements. For instance:

(1) I am using a pressure transducer with the output voltage of 10-32Vdc and Pressure range of 0-1.5 bar. I did my calculation (equation) for the data captured as follows:

Y=MX+B
Where,
Y=Output or engineering unit in bar
M=Slope scale factor = Pressure range/Output voltage = 1.5/32= 0.6818182
X= Input (volts) but it is a variable (data captured and read from the computer)
B= Offset = 10*M

Unfortunately, I have been getting a negative differential pressure value using the equation above. What can I do?

(2) The flow rate conversion curve which based on the use of frequency conversion to flow rate is not a straight line curve I generated the equation below based on the chart supplied by the manufacturer

Y= 0.0341X + 0.1119
Where X = the frequency data captured and read from the computer)

What can I do as the data captured are out of range?