Honeywell STR12D warranty Application Data, Where

Application Data*

34-ST-03-64 Page 15

Liquid Level: Closed Tank Determine the minimum and maximum pressure differentials to be measured (Figure 18).

PMin = (SGp x a) – (SGf x d)

=LRV when HP at bottom of tank

=–URV when LP at bottom of tank

PMax = (SGp x b) – (SGf x d)

=URV when HP at bottom of tank

=–LRV when LP at bottom of tank

Where:

Minimum level at 4 mA

Maximum level at 20 mA

a = distance between bottom tap and minimum level

b = distance between bottom tap and maximum level

d = distance between taps

SGf = Specific Gravity of capillary fill fluid (see page 11 for values)

SGp = Specific Gravity of process fluid

Max

Level

b

Min

Level

a

Transmitter above datum

Max

Level

	b
Min
Level		a

Transmitter at datum

Max

Level

b

Min

Levela

Transmitter below datum

LP

HP

LP

HP

LP

HP

24253

Figure 18—Closed tank liquid level measurement distances.

*Contact STC-Phoenix concerning applications for model STR13D.