text: With a gyromagnetic ratio 40.5% of that for H, P-NMR signals are observed near 202 MHz on an 11.7-Tesla magnet (used for 500 MHz H-NMR measurements).  Chemical shifts are typically referenced to 85% phosphoric acid, which is assigned the chemical shift of 0, and appear at positive values (downfield of the standard). Due to the inconsistent nuclear Overhauser effect, integrations are not useful.  Most often, spectra are recorded with protons decoupled.