Yokogawa RotaMASS 3-Series - Manual (Page 228)

11. TECHNICAl dATA
11-6 IM 01R04B04-00E-E 8th edition March 01, 2011 -00 All Rights Reserved. Copyright © 2003, Rota Yokogawa
Explosion proof Concept and Option /Hp
The detector is intrinsically safe, the converter flame
(explosion) proof (RCCF31) or intrinsically safe associated
apparatus (RCCR31). The driving power from converter to
detector is limited and protected by a barrier, which is part
of the converter. The barrier is protecting the detector either
for gas group IIC or IIB (option /HP). With option /HP the
detector driving power is higher which is benefit to 2 phase
flow. This is also true for non hazardous applications.
Option /KF2 delivers one passive intrinsic safe current
and one pulse output, however the converter is flame
(explosion) proof.
gas Measurement
For gas applications please choose the option /GA.
Density reading below 0.3 kg/l is not possible. Volume flow
is calculated by using the fix density value stored in „Reference
density“. Based on the selection of the gas density, the follow-
ing volume flow rates can be calculated; standard, reference,
normal and
operating. Besides, the corresponding volume flow rate units
can be selected. Some functions are unavailable for gas
measurement, including concentration measurement, empty pipe,
slug or corrosion detection.
Good and stress free installation is mandatory for a stable
Zero. Attention to resonance phenomenons has to be taken if
gas compressors are used in the pipe. Flow noise has to be
avoided.
Batch process
The specified mass flow accuracy applies if the batch
process is >1 minute. For shorter batch time (Dt in s) the
accuracy decreases with the quare root of 60/Dt.
For short batches the opening and closing times of the
valves have to be greater than 2 seconds.
density Measurement
We offer 3 levels of density measurement. The standard
adjustment (also /K4) delivers an accuracy up to 0.001 g/cm³, if the fluid density is around 1 kg/l. However, at elevated
temperatures the density error may increase. For option /K4 the instrument is preheated ensuring long term stability. However, if
high density stability is needed at high temperatures option /HT is recommended. Option /K6 includes preheating, a full calibration
at 3 different densities, increased temperature measurement specification and individual adjustment of the fluid temperature de-
pendency. For more information please see TI 01R04B04-05E ”Density Measurement with ROTAMASS”.
Overview density-/volume flow measurement:
Option Accuracy Certificate description Application
Standard ± 0.0015 g/cm³ to
± 0.008 g/cm³ Standard (mass flow)
factory calibration
certificate - Standard adjustment with water and air
- Density constants given in mass flow
certificate - Process medium and environment are
approximately at room temperature, the density
range is 0.9 kg/l to 1.1 kg/l
Option /K4 ± 0.001 g/cm³ Standard (mass flow)
factory calibration
certificate - Thermal treatment of the sensor and
special hardware design
- Standard adjustment with water and air
- Density constants given in mass flow
certificate - Improved volume flow accuracy
- Process medium up to 150°C, for higher
temperature select option /HT
- Density range is 0.9 kg/l to 1.1 kg/l
Option /K6 ± 0.0005 g/cm³ Separate factory
density calibration
certificate - Thermal treatment of the sensor and
special hardware design
- Density calibration with 3 different liquids
- Individual adjustment of the fluid
temperature dependency - Density and concentration measurement in
addition to the mass flow:
- Process medium up to 150°C, for higher
temperature select option /HT
- Density range 0.3 kg/l to 2 kg/l
- Best volume flow accuracy
Concentration Measurement for liquids
The Standard Concentration Measurement (option /CST)
is suitable for concentration measurement of emulsions or
suspensions, where the density of the solid is assumed to
be fix. It can also be used for (mainly low concentration)
solutions if the two fluids are not strongly interacting. The
density change of the liquid components due to temperature
can normally be described with a linear or quadratic function
with very high accuracy within the desired measurement
range. The coefficients of these function (linear and
quadratic thermal expansion coefficients) must be either
known or have to be determined prior to using this function.
For interacting liquids the Advanced Concentration
Measurement options should be used, these options
can be ordered using the appropriate /Cxx concentration
measurement option. For more information please see
TI 01R04B04-04E-E “Concentration Measurement with
ROTAMASS”.