I calibrated an LCD 1080p monitor to D65 targeting 90% white, which = ~95 nits, peak white being 120 nits, 2.2 gamma, using a budget 10 nm spectro.

Calibrated my Pioneer 60 inch Kuro Pro 150-FD using a 10% window to the same targets. Even though both displays measured just about the same in terms of x/y/Y, I perceived the the LCD as brighter and warmer than the Kuro.

Which display (plasma or LCD monitor) would be the best to use as the master display to obtain an alternate white point for an LG WOLED?

A larger display will always be perceived as brighter that a smaller display t the same nits value.
And unless you know the backlight type of the LCD it is impossible to know if it is suitable for a perceptual match.
But, I'd lean towards the Plasma.

Steve

Thanks, Steve. Corrected for the luminance difference and the LCD monitor was very much pushing red. Definitely reaffirmed my confidence in my trusty ol' Kuro.

Hi Steve, I wonder what backlight type of a LCD is suitable for a perceptual match? Thanks

CCFL tend to be good.
Although most narrow bandwidth LED backlights tend to be ok too.
Wide gamut ones can be too spikey.

Steve

Purchased an old CCFL monitor for the purposes of perceptual white point matching, calibrated it to D65 using my consumer spectro, and compared it side by side to my Kuro.
They were darn near a spot on match. CCFL is definitely suitable for this particular task.