Tankvision Calculations
Endress+Hauser 57
8.5.2 Measurement of ambient temperature
The CTSh should be calculated automatically, which is only possible if we also have the actual
ambient temperature measured automatically.
Tankvision is capable of integration of this temperature from field equipment. It can
redistribute this information over the whole or part of the Tank Farm. This makes it possible
to use one ambient temperature sensor and use the measure temperature for one or more
tanks within the same Tankvision system.
Automatic measurement of ambient temperature on site
Exact recommendations on the location, installation and accuracy of the Ambient
Temperature sensor are vague. The sensor should be located in the outside environment, be
protected from direct sun shine, rain and wind, and preferable be approximately 1 meter (3
ft) from any building or large object.
An external Ambient Temperature sensor can be connected via:
• NRF590 – for example by adding an extra HART converter with temperature sensor, or by
using the optional RTD input
• Proservo NMS53x – as above
Other methods may also possible be possible, depending on installed equipment and used
field protocol. Please consult Endress+Hauser.
Later we will also see that there is a special setting in Tankvision where we can disable fail
propagation if the ambient temperature doesn’t work. After all it would be pretty horrific if
the calculated inventory data of all tanks is suddenly useless, just because one sensor fails.
Manual entry of ambient temperature
It is also possible to enter the ambient Temperature manual.
This could be used, for either verifying the CTSh calculations, or in the unlikely case the
ambient temperature is in fail.
8.6 Alcohol calculations
8.6.1 The OIML R22
The OIML R22, as issued in 1975 deals with the calculations for the basic data "relating to
the density and to the alcoholic strengths by mass and by volume of mixtures of water and
ethanol". As per OIML R22 standards the range is -20 to +40 °C (-4 to +104 °F) and defines
the following:
•Table I:
Gives the Observe density as a function of the temperature and the alcohol strength by
mass
• Table II:
Gives the Observe density as a function of the temperature and the alcohol strength by
volume
• Table IIIA and IIIB:
Gives the standard (reference) density at 20 °C (68 °F) (Table IIIA) and the alcoholic
strength by volume (Table IIIB) as a function of the alcoholic strength by mass
• Table IVA and IVB:
Gives the standard density at 20 °C (68 °F) (Table IVA) and the alcoholic strength by mass
(Table IVB) as a function of the alcohol strength by volume
• Table VA and VB:
Gives the acloholic strength by mass (Table VA) and the alcoholic strength by volume
(Table VB) as a function of the observe density at 20 °C (68 °F)
•Table VI:
Gives the alcoholic strength by mass as a function of the observe density and temperature
•Table VII:
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