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A.4 setting range values (local zero and span) – Honeywell ST 3000 User Manual

Page 67

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A.4

Setting Range Values (Local Zero and Span),

Continued

Procedure, continued

Table A-3

Setting Range Values Using Local Zero and Span

Adjustments,

Continued

Step Action

7

Using an accurate pressure source, apply pressure equivalent to

desired upper range value to transmitter.

ATTENTION For differential pressure transmitters, apply pressure

to the high pressure head and be sure that the pressure to the low

pressure head is at its reference value.

8

Check that milliammeter reading is 20 mA.

If reading …

Then…

is not exactly 20 mA

go to Step 9.

is correct

go to Step 10.

ATTENTION If you have the smart meter with local zero and

span adjustment option, you may substitute the smart meter readings

for the milliammeter readings. For example, with URV input pressure

applied assume that the meter reads 396 inH2O instead of 400

inH2O. In this case, the meter reading is less than 100% (or 20 mA).

9

a. Press and hold SPAN button on local zero and span assembly or

smart meter.

ATTENTION The smart meter readings revert to the default unit of

percent (%) during this operation. If the error code Er0 appears on

the display, you are working with a model STD110 transmitter that

does not support the local zero and span adjustments. If the error

code Er4 appears, you are trying to set a SPAN value that is outside

acceptable limits for your transmitter. Readjust applied pressure to

be within acceptable range limits and repeat this procedure.

b. Press

Increase

button once to complete this function.

ATTENTION The smart meter display goes blank for a 1/2

second and then returns reading 100%.


c. Check that milliammeter reading equals 20 mA and release SPAN

button.

ATTENTION If milliammeter reading doesn’t change, be sure you

are not working with a model STD110 transmitter that ignores local

adjustments. The smart meter readings return to the set engineering

units after you release the SPAN button.

Continued on next page

2/05

ST 3000 Release 300 Installation Guide

57