background image

 

 

 

 

  SA_001_2019-07_10.00  Transmitter PASCAL Ci4 

Page 2/4 

General Information 

These SIL Instructions contain information and instructions for using the device as part of 
your  protection  system  according  to  IEC/EN  61508.  In  addition  to  these  instructions, 
please take all relevant legal requirements, applicable standards as well as the additional 
technical  specifications  on  the  accompanying  data  sheet  into  account  (see 
www.labom.com). 

  

1.1  Safe Function 

The safe functio

n of the device according to IEC/EN 61508 is the 4…20 mA current signal. 

  

1.2  Validity 

The safe function can only be guaranteed if the option "Func-
tional safety according to IEC/EN 61508" has been chosen for 
the device. These devices are marked as shown on the right. 

 

SIL marking on the unit. 

  

Technical Data 

The following technical data applies to the safe function of the device. 

  

2.1  Accuracy 

Assured accuracy in safe mode: 1% 

  

For devices with diaphragm seal take the error of the diaphragm seal into account as well.  

  

For devices with ATC-option the accuracy for devices without ATC-option applies only.  

  

Please  observe  that  for  devices  with  operating  software  for  level  applications  inaccurate 
level parameters directly affect the accuracy of the level calculation. E. g. the less accurate 
the density is set, the more the calculated level deviates from the actual level. 

  

2.2  Reaction Times 

  In the event of a request: 220 ms 

  In the event of fault detection: 100 ms 

  

Note that any set damping value can extend the reaction time in the event of a request.  

  

Additional elements in the process connection, such as capillaries, can extend the reaction 
time in the event of sudden pressure changes in the process. 

  

2.3  Start-up Behaviour 

A  safe  state  is  also  guaranteed  during  initialisation  or  a  phase  of  low  voltage.  After  con-
necting the supply voltage,  a current  of < 3.6 mA (alarm current) is issued at  the current 
output.  Following  completion  of  initialisation,  after  about  5  seconds,  the  current  output 
jumps to a current proportional to the applied pressure or approaches the correct current 
according to the set damping value. 

  

Summary of Contents for CI4 Series

Page 1: ...e Fraction SFF 95 29 Failure rate for safe detected failures SD 1 81 10 7 1 h Failure rate for safe undetected fail ures SU 3 11 10 7 1 h Failure rate for dangerous detected failures DD 3 42 10 7 1 h Failure rate for dangerous undetected failures DU 4 13 10 8 1 h Probability of a dangerous undetect ed failure per hour PFH 4 13 10 8 1 h Mean time between failures Mean time to failure MTBF MTTF 130 ...

Page 2: ... of the diaphragm seal into account as well For devices with ATC option the accuracy for devices without ATC option applies only Please observe that for devices with operating software for level applications inaccurate level parameters directly affect the accuracy of the level calculation E g the less accurate the density is set the more the calculated level deviates from the actual level 2 2 Reac...

Page 3: ...proportional to the pressure when using the table function for example to map the tank shape when measuring the level A fault in the support points of the table leads to a faulty signal current There is a linear interpolation of the measurement between these support points This reduces the accuracy between the support points When using the table function in SIL application the operator should ther...

Page 4: ... certain ty during regular inspections The operator can define the inspection interval depending on the PFD value required Not only the device but the complete measuring chain should be tested during inspection It is the responsibility of the plant operator to determine an adequate test of the safety function The following inspection procedure is recommended for the device to achieve a high fault ...

Reviews: