ASTM Hydrometers and Thermohydrometers
For density, relative density (specific gravity) or API gravity
determination of crude petroleum, liquid petroleum products and mixtures
of petroleum and non-petroleum products.
Calibrated hydrometers and thermohydrometers are available
from Koehler with an ISO/IEC 17025 and ANSI/NCSL Z-540-1 Report of
When inquiring about calibrated hydrometers and
thermohydrometers, please refer to the catalog number for the
corresponding hydrometer or thermohydrometer and replace the middle
three zeros in the catalog number with 004. Example: 251-000-01H API
Gravity Hydrometer would be 251-004-01H Certified API Gravity
Conforming to the specifications of: ASTM E100
Applicable Test Method Standards
ASTM D287, D1298, D6074, D6158; API MPMS Chapter 9.1; IP 160; ISO 3675; DIN 51757
Standard temperature 60°F, subdivisions 0.1° API, length 380mm, temperature scale F 30-220
ASTM Thermohydrometer No.
Nominal API Gravity Range, deg.
-1 to 11
9 to 29
19 to 31
29 to 41