Honeywell STR12D - Manual (Page 14)

34-ST-03-64
Page 14
Note: A minimum of 250 ohms
of loop resistance is necessary
to support communications.
Loop resistance equals barrier
resistance plus wire resistance
plus receiver resistance.
= Operating Area
0 10.8 16.28 20.63 25 28.3 37.0 42.4
1440
1200
800
650
450
250
Operating Voltage (Vdc)
Loop
Resistance
(ohms)
Note: A minimum of 250 ohms
of loop resistance is necessary
to support communications.
Loop resistance equals barrier
resistance plus wire resistance
plus receiver resistance.
= Operating Area
0 10.8 16.28 20.63 25 28.3 37.0 42.4
1440
1200
800
650
450
250
Operating Voltage (Vdc)
Loop
Resistance
(ohms)
Figure 16—Supply voltage/loop resistance chart.
Variable ref. leg
Head
H1
LP Side
HP Side
H2
Fixed
24249
Maximum level
Minimum level
.
NOTE: Lower flange seal should not be mounted over 22 feet below or above
the transmitter for silicone fill fluid (11 feet for CTFE fill fluid) with tank at one
atmosphere. The combination of tank vacuum and high pressure capillary
head effect should not exceed 9 psi vacuum (300 mmHg absolute).
Consult Honeywell for installation of STR13D.
Figure 17—The ST 3000 transmitter with remote diaphragm seals shown mounted on a tank.