Colorimeters based on the 1931 observer do not provide enough information to compute tristimulus coordinates with respect to these other observers unless some additional facts about the stimulus are known. As colorimeters age, their filter properties can change, sometimes drastically. Although I don't think you really have to send the devices back to the manufacturer for recalibration as often as the manufacturers recommend, you do want to keep an eye on your device. One good strategy is to pick some standard lighting configuration in your lab and measure it when you first buy your instrument. You can then remeasure this configuration periodically.
Drastic changes are a cause for concern.
For spectral radiometers, measuring a fluorescent lamp is useful because you can make sure the lamp's spectral lines show up where they are supposed to. A radiometer takes the incident photons and measures those in each waveband separately, so that the noise for each measurement is greater. My radiometer has difficulty at the low end of my monitor's gamma curves. Spectral radiometers vary considerably in how finely they sample the spectrum. It is possible to pay a lot of money and get sampling every nanometer or pay a lot less money and get sampling every 10 nm.