Hello Yunus,
Please see below for responses to your questions.
1 - Customer has a sale & check meter (coriolis) connected in series for custody transfer application & informed that both these reading were not matching. Please explain what might be the possible reasons for this mis match.
There could be a number of reasons for this mis-match. Before providing the most common possibilities could you please answer the following questions? Is this a gas or liquid application? What is the amount of difference between the two meters? Is the difference consistent, or does it fluctuate? What is the distance between the two meters and what equipment is between the two meters? Is the sale meter also a Coriolis or is it a different technology? Coriolis meters also have excellent diagnostic capabilities which can provide insight to a problem if there happens to be an issue with one of the meters. If possible, you can perform data logging to obtain insight to any potential issues.
2- When a meter is supplied from the factory what is the calibration validity time?
The calibration of the coriolis meter from the factory is valid for the life of the meter unless there is damage to the meter tube stiffness as a result of erosion or corrosion. Micro Motion Coriolis meters can be ordered with Smart Meter Verification, an onboard diagnostic that can provide confirmation of any change in the meter performance – it is worth checking to see if the meter in question has Smart Meter Verification and to pull the last 20 results from the transmitter to indicate if any performance change has occurred.
3- what is difference between meter factor & k factor & are there any conditions & situation when an operator can change it ?
Meter Factor is a value obtained by dividing the actual volume of liquid passed through a meter as measured by the prover during proving by the corresponding volume registered by that meter at standard conditions. The meter factor is used to adjust the meter’s indicated volume to the gross measured volume.
K-Factor is a value determined during a calibration of the meter. K-Factor typically represents a number of pulses required per unit of volume (i.e. – xxx number of pulses = 1 barrel)
It is common for an operator to change a meter factor after a meter prove. Application of a meter factor allows the k-factor to remain constant. Adjusting or changing the k-factor is much less common since it changes the pulse output per unit of volume for the meter. There are very few instances in which an operator should be changing the k-factor.
4- When there are 2 pulse outputs from a transmitter with 90 degree phase shift , what is it signifying ,like kind of if one pulse output not working the other takes it place is it right understanding?
The two pulse outputs are redundant, therefore if one is not working the other takes its place. Dual pulse is also used in proving applications to make sure that there is no discrepancy between the two pulse outputs.
5- If a customer has an RS 485 output from transmitter ,then it can be possible to fetch multi variable data like volume, mass, temperature from the transmitter using a single RS 485 Communication signal to connect to host system ,is it right ?
Correct. Modbus RS-485 can be used to get multivariable data such as mass flow, volume flow, and temperature using a single RS-485 connection from the transmitter to the host system that will accept this Modbus signal. Micro Motion transmitter manuals indicate which registers contain the variables in question.
Should you have any other questions please do not hesitate to contact me.
Regards,
Stephen
Stephen C. Anson | Sr. Manager, Midstream | Flow Solutions
Emerson Automation Solutions | 7070 Winchester Cir | Boulder | CO | 80301 | USA
T +1 303 200 6786 | M +1 303 204 3569 | stephen.anson@emerson.com