Dry bulb, Wet bulb & RH calculations

[HencoV]

@ the forum experts...
I am trying to get a meaningful calculated Wet bulb value from an RH & temperature probe. Problem is..when calculating WB from DB & RH, I get one value. (formula using iteration from https://www.weather.gov/epz/wxcalc_rh) Testing the RH value using DB & calculated WB gives a different RH (http://www.1728.org/relhum.htm)..also, I have an excel spread sheet that I've been using all along to calculate RH& EMC. The answers I get from excel corresponds with 1728.org.

eg. weather.gov...DB 60 deg C, RH 30.1% = WB 36.31 Deg C
1728.org & my spread sheet: DB 60 Deg C, WB 36.31 deg c = RH 22%

btw..The reason i'm trying to calculate a WB value from an RH probe is to control vent on WB ...not on RH or EMC, as it fluctuates to much with DB temp fluctuations

[HencoV]

..The Higher the temperature and RH, the smaller the error...