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18

…5

ADVANCED CONFIGURATION LEVEL

5.1.2

Relative Humidity (RH)

The relative humidity calculation requires two inputs, one from a wet-bulb sensor and one from a dry-bulb sensor. Both of these
inputs are configured as variables. RH tables are based on the use of an aspirated psychrometer having an air velocity of at least
11.5 feet per second or 3.5 meters per second across the bulb sensors.

Note. Inputs used for wet- and dry-bulb measurement must be in the ranges 32 to 212

°

F or 0 to 100

°

C .

5.1.3

Mass Flow 1 and 2

The two types of mass flow calculations available are as follows:

Mass Flow 1

 – applications where a volumetric flow meter is used to measure flow.

Mass Flow 2 

– applications where a differential pressure transmitter is used to measure flow.

The standard formula for mass flow 1 is as follows:

P
T

T

r

P

r

M = k  V

where:

k = Scaling constant
V = Input a (input from volume flow source)
P = Pressure (pressure input source)
T = Temperature (temperature input source)
T

r

 = Reference temperature (for the scaling constant used)

P

r

 = Reference pressure (for the scaling constant used)

The temperature units used by the input source must be specified, since all calculations use absolute temperatures and
conversion is made if the input uses 

°

F or 

°

C.

The standard formula for mass flow 2 is as follows:
(i)

h  P T

r

    T  P

r

M = k  

where:

h = differential pressure head

Some differential pressure sensors incorporate a square root linearizer and therefore produce an output linear to flow. In these
instances no additional linearization within the C1900 is required. Where the input from the differential pressure sensor is linear
to differential pressure head the square root linearizer within the C1900, must be selected in the 

Linearizer Type

 frame in the 

Set

Up Input Page

BASIC CONFIGURATION LEVEL

.

Therefore the formula used internally within the C1900 is:
(ii)

P
T

Tr

Pr

M = k   a

where:

a = linearized flow signal

The linearized flow signal is produced by the transmitter or derived from the signal linearized within the C1900.

Maths

Summary of Contents for COMMANDER 1900 Series

Page 1: ...User Guide Advanced Software Options COMMANDER 1900 Series Circular Chart Recorders COMMANDER 1900 100 3 198 5 dEGF OP54 5 200 5 50 8...

Page 2: ...nditions result in degraded process system performance leading to personal injury or death Therefore comply fully with all Warning and Caution notices Information in this manual is intended only to as...

Page 3: ...g the Engineering Flow Rate 12 4 1 2 Calculating the Count Rate High 12 4 2 Set Up Totalizer 14 Maths 5 ADVANCED CONFIGURATION LEVEL 17 5 1 Introduction to Maths 17 5 1 1 Standard Maths Block 17 5 1 2...

Page 4: ..._ Soak Time Adjust SK AdJ ______ Run Hold Source r hSrc ______ Reset Enable rESEt ______ Skip Enable SKIP ______ SKIP b ______ Self Seeking S P SS SPt ______ Retort rEtOrt ______ Ramp Soak Profile Pro...

Page 5: ...sary delays when a program is started see Fig 2 5 Retort function ensures safe operation under fault conditions see Fig 2 6 Power recovery function determines ramp soak profile restart position on ins...

Page 6: ...Soak Adjust function allows the Soak time of a segment to be extended or reduced by a value preset in the Soak Adjust frame in the Ramp Soak Profile Control Page The soak time can be adjusted repeated...

Page 7: ...e Power Down Recovery Function is only available on instruments fitted with the Timer option The Power Recovery function allows pre selection of the restart position within a ramp soak profile when po...

Page 8: ...ctivate program run hold The run hold source is level triggered i e the active logic state must be maintained to select the alternative function If a program is activated or placed into operator hold...

Page 9: ...he Profile States Page OPERATOR LEVEL Skip Enable Select ENBL Y to enable or ENBL N to disable the Skip Segment frames in the Profile States Page OPERATOR LEVEL Self Seeking Set Point If ON is selecte...

Page 10: ...ss an intermediate spacer segment is used Segment End Value Set the segment end value If segment start end values are the same Soak advance to the Soak Time frame If segment start end values are diffe...

Page 11: ...The value set applies above and below the Process Variable Setting 0 turns off the holdback hysteresis function A guaranteed ramp or soak is a segment whose time is counted only if the process variabl...

Page 12: ...total 1 Total 1 external counter drive Wrap around and count only available if totalizer option fitted MAN x AUtO x Control mode selected for controller 1 or 2 Manual control Automatic control 2Nd x...

Page 13: ...Rate D P dEC Pt ____ Count Rate Low CNt LO ____ CUtOFF ____ PrESEt tOtL _ Reset Controls Stop Go Controls rESEt ______ rSt SrC ______ Reset Source StOPGO ______ Stop Go Source SG SrC ______ Set Up Cl...

Page 14: ...their own power supplies can be driven using 4 relay and digital output module options 4 1 1 Converting the Engineering Flow Rate Example A and B To calculate the count rate high the engineering flow...

Page 15: ...2500 0 Preset Value Predetermine d Value Preset Predetermine d Count Count Up 9999 0000 0000 Count Rate High Low CNt HI 06 94 CNt LO 0000 Count Direction Preset Value Predetermine d Value Count Up Wra...

Page 16: ...e right Secure Reset The Secure Total may be reset to either 00000000 or 99999999 depending on the count direction if required Select YES to reset the counter or NO to retain the current counter value...

Page 17: ...termined Value CNtdIr dN decremental counter Preset Value Predetermined Value Predetermined Value If the wrap around facility is used see below the front panel total is automatically reset to the Pres...

Page 18: ...itted when the Predetermined Value is reached Reset Enable Select ENBL Y to enable or ENAbL N to disable the counter reset frame in the Totals Page OPERATOR LEVEL Reset Source Select the digital sourc...

Page 19: ...end The example below shows the construction of a maths block for the following equation 5 ADVANCED CONFIGURATION LEVEL Maths Element 1 Constant 8 Constant 1 Maths Block 4 Maths Block 1 Input 6 Input...

Page 20: ...essure input source T Temperature temperature input source Tr Reference temperature for the scaling constant used Pr Reference pressure for the scaling constant used The temperature units used by the...

Page 21: ...sition F B 1 Remote S P 1 Local S P 1 Process Variable 1 Input A Input t Constant 8 Constant 1 Maths Block 4 Maths Block 1 Input 6 Input 1 Channel 1 2 Output Channel 1 2 Output cool Channel 1 2 Output...

Page 22: ...ition F B 1 Remote S P 1 Local S P 1 Process Variable 1 None Input a Input t Constant 8 Constant 1 Maths Block 4 Maths Block 1 Input 6 Input 1 Channel 1 2 Output Channel 1 2 Output cool Channel 1 2 Ou...

Page 23: ...erage reset signal 5 1 5 Real Time Average The real time average function averages a continually varying input over a set time scale between 1 and 1440 minutes 24 hours Any process variable remote set...

Page 24: ...ock Function Select the maths block function required AVErGE Averages a continually varying input over a set period of time LO VAL Holds minimum value measured on input variable HI VAL Holds maximum v...

Page 25: ...nt 4 operator 2 Select the operator required for element 4 For description of operators refer to Maths Block n Element 2 frame Maths Block n Element 5 operand 3 Select the source required for element...

Page 26: ...Return to Select Maths Function frame Maths High low Input Select the variable source whose minimum or maximum value is to be detected For a description of input output sources refer to Table 5 1 on p...

Page 27: ...e Temperature Decimal Point Set the number of decimal places required for the reference temperature 0 to 3 places Pressure Input Select the process variable source required for the pressure input Pres...

Page 28: ...3 Process variable 4 Process variable 3 PFb 1 rSP 1 2 SP 1 LSP 1 SP 1 PV 1 NONE No source required Position Feedback 1 Remote set point 1 Local set point 1 Set point 1 Process variable 1 Heat cool on...

Page 29: ...et point If the maths result is to be assigned to a process variable or remote set point it is necessary to set up fault detection levels broken sensor actions and an engineering range high low in the...

Page 30: ...on specific days hours or minutes for an exact period of time Timer ON OFF states can be used to energize relay outputs acknowledge alarms stop the chart select auto manual control modes and local rem...

Page 31: ...isabled on hour set to All on minute set to 20 minutes duration in hours set to 0 hours duration in minutes set to 40 minutes Relay On Monday 00 20am Relay Off 01 00am 01 20am 02 00am 02 20am 03 00am...

Page 32: ...Select ON to enable or OFF to disable Tuesday Enable Repeat as above for Tuesday to Sunday On Hour Set the hour at which the timer becomes active If ALL is selected the timer becomes active every hour...

Page 33: ...day and time are correct in the above frames select NO to return to the Set Up Clock frame To set the clock s date day or time select YES Year Set the year Month Set the month Date Set the date Day S...

Page 34: ...32 NOTES...

Page 35: ...ion pH conductivity and dissolved oxygen transmitters and sensors ammonia nitrate phosphate silica sodium chloride fluoride dissolved oxygen and hydrazine analyzers Zirconia oxygen analyzers katharome...

Page 36: ...notice ABB 2001 Printed in UK 02 01 ABB Automation Ltd Howard Road St Neots Cambridgeshire PE19 8EU UK Tel 44 0 1480 475 321 Fax 44 0 1480 217 948 ABB Automation Inc 125 E County Line Road Warminster...

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