Background: I recently started a project to produce a certain type of equipment. The (multiple) units sense and amplify small voltages on the order of 1 mV and then process the information digitally. My intention has always been to *digitally* calibrate the units, to each other (important for this application) and to an absolute standard by using a precision signal generator of some sort. The calibration will, at first order, be a simple storage of the actual (as opposed to the theoretical designed) gains and offsets of the individual units. These numbers can be stored in a file, used to calibrate the information used, and periodically updated to compensate any drift over time. Later, if it turns out to be important for the application (doubtful) I may want to even digitally compensate for weak nonlinearities.
Question: Can anyone help me find a *precision* signal generator, commercial or home made, or any other suggestions to solve this problem. On the low end of things if I could get just a precise 1 mV signal (sine or square wave) that would be a great start. If there is a *precision* way to step down a 1 V signal to a 1 mV one then I could use an ordinary commercial signal generator. My impression is the commercial signal generators are not designed to be precise (or work at all) at the 1 mV level. There are cheap signal generators that generate test signals at this level such as ECG model simulators, but these are toys, and there is *nothing* precise about them. I need a gold standard. I only need very low frequencies < 1000 Hz. Surely there must be an economical and reasonable way to either step down a commercial signal generator in a very *precise* way or to generate the signals some other way. But obviously most home made solutions I can think of would have themselves to be calibrated, and so defeat the purpose.
If anyone has any ideas about this I would really appreciate it.
Question: Can anyone help me find a *precision* signal generator, commercial or home made, or any other suggestions to solve this problem. On the low end of things if I could get just a precise 1 mV signal (sine or square wave) that would be a great start. If there is a *precision* way to step down a 1 V signal to a 1 mV one then I could use an ordinary commercial signal generator. My impression is the commercial signal generators are not designed to be precise (or work at all) at the 1 mV level. There are cheap signal generators that generate test signals at this level such as ECG model simulators, but these are toys, and there is *nothing* precise about them. I need a gold standard. I only need very low frequencies < 1000 Hz. Surely there must be an economical and reasonable way to either step down a commercial signal generator in a very *precise* way or to generate the signals some other way. But obviously most home made solutions I can think of would have themselves to be calibrated, and so defeat the purpose.
If anyone has any ideas about this I would really appreciate it.
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