Den
sity,
speed of
sound, and vi
sco
sity of natural geothermal water
s from the Ea
st Tur
key Geothermal Field have been mea
sured over the temperature range from 278 to 363 K and at atmo
spheric pre
ssure. The mea
surement
s were made u
sing the Anton Paar DSA 5000 M
sound-
speed analyzer and the Stabinger SVM3000 vi
scometer for two natural geothermal water
sample
s from the Ke
kli
k Mağara
si and Afyon well
s. A
sound-
speed analyzer (Anton Paar DSA 5000 M) wa
s u
sed to
simultaneou
sly mea
sure of the
speed of
sound and the den
sity of the
same geothermal water
sample
s. The
standard uncertainty of the den
sity, vi
sco
sity, and
speed of
sound mea
surement
s i
s e
stimated to be 0.01%, 0.25%, and 0.05%, re
spectively. Mea
sured value
s of den
sity and
speed of
sound were u
sed to calculate other derived
key thermodynamic propertie
s of the geothermal water
s, which are very important for environmental impact optimization of a geothermal energy production operation. The propertie
s mea
sured at atmo
spheric pre
ssure have been u
sed a
s reference data for prediction of high-pre
ssure propertie
s of the geothermal water
s.