How to configure a shell and tube heat exchanger with Lab VIew to get data

Question

HiI
In our undergraduate chemical engineering labboratory we want to configure our shell and tube heat exchanger  with a DAq and Lab VIEW to get information about the temperaure (of the cold fluid stream being heated), the pressure (of the steam on the shell side of the heat exchanger) and the flowrate (of the water being heated).
Can anyone suggest thermocouples, pressure transducers and flowmeters to fit between the heat exchanger and the DAq?
P.S. the heat exchanger is already fitted with thermometers, a pressure gauge and a rotameter but we don't know how to connect these hardware to the DAq
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Answer 1

It sounds like you have enough information to pick out appropriate sensors, you just need to do the research. I would start looking through the Omega catalog, or give them a call - they're usually helpful. I can't take the time to spec out parts for you - that would be a lot of time spent on someone else's project. Most pressure sensors put out either a 4-20mA or 0-5V signal, either of which you can read through an analog input on a DAQ; measuring a 4-20mA signal requires a resistor to convert to voltage. Most of the NI DAQ boards can read a thermocouple on an analog input, but make sure that your hardware does support reading thermocouples. For accurate readings, use a device that has built-in cold junction compensation - for example, the SCB-68 connector block - and for the most accurate readings, get a board specifically designed for temperature measurement.
For the flow measurement, a standard, simple solution is an orifice plate. You put a differential pressure transducer across it, look up the appropriate equations, and use them to calculate the flow rate given the density of the fluid (which you'll be able to calculate from the pressure and temperature, since steam tables are widely available). There are other differential pressure devices available as well - at a previous job we used a V-Cone from McCrometer. If you call them they'll spec one for you - but get an approximate cost first to make sure it's within your budget.