Calibration of data acquisition and multichannel measurement systems
A multichannel system is not one instrument, it is thirty-two instruments that are assumed to agree with each other. That assumption is rarely tested, and when it fails it fails silently.
Inter-channel consistency is the thing nobody checks
A single-channel error announces itself: the number looks wrong. An inter-channel error does not. Every channel produces a plausible reading and the array as a whole produces a plausible result — but any measurement that depends on the relationship between channels is now wrong. Sound intensity, transfer functions, transmission loss, modal analysis, beamforming and array localisation all depend on exactly that relationship.
A small gain difference or a phase mismatch between two channels does not make the data look broken. It makes it look slightly different from last time, which is the most expensive kind of wrong.
- Channel sensitivity and gain, per channel rather than for the unit as a whole.
- Frequency response across the working range of each channel.
- Inter-channel amplitude and phase consistency — the measurement that matters for intensity, FRF and array work.
- Calibration against traceable reference signal generators, with the reference chain documented.
- The whole chain as you use it: transducer, cable, conditioning and acquisition together, not the acquisition card in isolation.
Traceable, outside the accredited scope
Certificate 24-LB0054 covers sound level meters, sound calibrators and measurement microphones only. DAQ and multichannel system calibration is performed to method against traceable references and the certificate states exactly that. For internal quality systems and for R&D comparability this is what is needed; if a regulator requires an accredited result for this equipment, we will tell you at enquiry.
How many channels can you handle?
Tell us the system and the channel count at enquiry and we will confirm before you ship. What we need to know is the transducer type, the conditioning arrangement and whether you need inter-channel phase checked as well as amplitude.
Should the transducers come too?
Yes, if you want the answer to mean anything. The system measures as a chain and calibrating the acquisition hardware alone leaves the largest source of error — the transducer — unmeasured.