Final answer:
The PSP plate can glow numerous times depending on the experimental context. In spectral data collection, it might 'glow' as many as 5000 times in one night, while in biological fluorescence measurements it might glow at set intervals, such as every 5 minutes over a certain time period.
Step-by-step explanation:
The PSP plate, presumably referring to a photostimulated phosphorescence or a photographic plate used in spectroscopy, glows when it is exposed to light during spectroscopy measurements. The question of how many times the plate glows could be interpreted in a few ways, depending on the context. If we're discussing the capture of spectral data, you could theoretically capture as many as 5000 spectra in one night, which might be translated to 5000 instances of 'glowing' as each spectrum is captured - assuming perfect weather conditions allow for uninterrupted data collection. This high throughput is made possible by the quick interchange of pre-drilled aluminum plates.
During experiments in a biological context, such as measuring the fluorescence changes in the blood, the plate or detection device might glow each time a measurement is taken. For instance, in the provided reference, fluorescence was measured every 5 minutes over a 60 minute period, which means the detection device would register 12 instances of 'glowing' in this context before the addition of an enzyme (like calf PNP) changes the fluorescence characteristics.