14 capillary fill fluid density compensation, Capillary fill fluid density compensation -24, Caution – Yokogawa EJX115A User Manual

Page 37

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<3. Parameter Setting>

3-24

IM 01C25T01-06EN

NOTE

No status output signal has been defined for a

CPU failure or hardware error. Use a 4-20 mA

signal to indicate a transmitter’s failure.

Status output for higher alert value

Status output for lower alert value

F0309.ai

Output

(%)

Status output

Status output

*: 5% of setting span for differential pressure / pressure

Time (t)

Time (t)

Setting

value

Setting

value

5%* of hysteresis

Output

(%)

5%* of hysteresis

On

Off

On

On

On

Off

Example: Status output operation of

ON

WHEN AL. DETECT

Figure 3.2 Status Output

(2) Selecting of output signal
Status output can be selected for the contact

output.

• Procedure to call up the display

DD and DTM

(excluding EJX_

HART 5[1.2])

[Root Menu] → Detailed setup

→Output condition → Process Alerts

→ DO config → DO Signal type

EJX_HART 5

[1.2] DTM

Configuration → Process Alerts →

DO Signal type

ON WHEN AL.

DETECT

Output is “ON” when alert is detected

OFF WHEN AL.

DETECT

Output is “OFF” when alert is

detected

CAUTION

Whenever turning on the transmitter or detecting

the short interruption, check if contact output

correctly reflects the alarm status and test

the ON/OFF action of contact output by the

parameter

DO test to confirm that the contact

output operates correctly.

3.3.14 Capillary Fill Fluid Density

Compensation

For transmitters with diaphragm seals, this function

is used to compensate the zero shift caused by the

ambient temperature effect on the capillary tubes.
The following equation indicates the relationship

between the calculated output value and the

compensating constant K (%/°C) with the measured

ambient temperature at the capsule module.

Compensated output = output + K × Temp

(1) Temperature Compensation Mode Setup

When using this function, set

T.Z. Cmp mode

to On to enable or Off to disable. To set to

On, follow the procedure below.

• Procedure to call up the display

DD and DTM

(excluding EJX_

HART 5[1.2])

[Root Menu] → Detailed setup

→ Signal condition → T.Z.

Comp menu →

EJX_HART 5[1.2]

DTM

Configuration → Pressure

Sensor →

→ T.Z. Comp mode

Select “On” or “Off”

Select “On” at the

T.Z. Cmp mode display

(2) Zero Shift Compensation Setup

Obtain the K compensating value from the

equation (a) below, and enter the value to

Temp

Zero.

K=

×100.............. (a)

– h×B

Span

where,

B: Constant value of fill fluid (See Table A.)
Span: |URV – LRV|
h: Distance from high pressure side to low

pressure side (m)

EJX118A/EJA118E: Distance from high side

of diaphragm seal to low side of diaphragm

seal.

EJX438A/EJA438E: Distance from

diaphragm seal (high side) to position of

transmitter (low side).

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