Setra System GCT-225 - Manual (Page 6)

6
4.2 Voltage Output Span Adjustment
(Complete the zero adjustment before setting span.)
Span or full scale output adjustments should only be performed by using an
accurate pressure standard (electronic manometer, digital pressure gauge, etc.),
with at least comparable accuracy to the GCT225 transducer (
±0.25% FS). With full
range pressure applied to the pressure port, the span may be adjusted by turning
the span potentiometer screw. The span (full scale) output is factory set to within
±25mV for 5 VDC FSO output or ±50mV for 0 to 10 VDC FSO output.
4.3 Current Output Zero Adjustment
While monitoring the current output , and with the pressure port open to
atmosphere or with zero pressure applied, the zero may be adjusted by
turning the zero potentiometer screw. The factory setting is 4mA (
±0.08mA).
For absolute pressure ranges, the zero should be adjusted with a full vacuum
applied. For compound pressure ranges, the zero should be adjusted with
the unit at atmospheric pressure and the output adjusted as noted in
Diagram 6 below.
Note: When it is not possible to vent input pressure for zero adjustment (ie., hazardous gasses), zero may
be adjusted by pulling a vacuum and setting the unit to 4.0 mA (
±0.08 mA). This method may result in a
small zero setting error due to variations in barometric pressure.
4.4 Current Output Span Adjustment
Span or full scale output adjustments should only be performed by using an
accurate pressure standard (electronic manometer, digital pressure gauge, etc.)
with at least comparable accuracy to the GCT225 transducer (
±0.25% FS). With full
range pressure applied to the pressure port, the span may be adjusted by turning
the span potentiometer screw. The span (full scale) output is factory set to within
±0.08mA.
5.0 Model 225 PERFORMANCE SPECIFICATIONS
Accuracy RSS * Thermal Effects
(at constant temperature.)
±0.25% FS
Comp Range
°F(°C)
Non-Linearity, BFSL
±0.15% FS
+15 to +150 (-9 to +65)
Hysteresis 0.20% FS Zero Shift
Non-Repeatability 0.02% FS %FS/100
°F (50°C)
2.0 (1.8)
*RSS of Non-Linearity, Non-Repeatability and Hysteresis. Span Shift
Environmental Data %FS/100
°F (50°C)
2.0 (1.8)
Temperature Warm-up Shift <
±0.1% FS total
Operating**
°F(°C)
-40 to +185 (-40 to 85)
Storage
°F(°C)
-40 to +185 (-40 to 85)
Current unit ordered with Option N1:
Operating**
°F (°C)
-22 to +176 (-30 to +80)
Storage
°F (°C)
-22 to +176 (-30 to +80)
**Operating temperature limits of the electronics only. Pressure media temperatures may be considerably higher or lower.
NOMINAL “INSTALLED” OUTPUT AT ATMOSPHERIC PRESSURE
PSI COMPOUND CURRENT
RANGE OUTPUT (mA)
-14.7 to 25 9.92
-14.7 to 50 7.63
-14.7 to 100 6.05
-14.7 to 250 4.89
-14.7 to 500 4.46
-14.7 to 1000 4.23
-14.7 to 3000 4.08
Diagram 6
BAR COMPOUND CURRENT
RANGE OUTPUT (mA)
-1 to 1.7 9.92
-1 to 3.4 7.63
-1 to 7 6.00
-1 to 17 4.88
-1 to 35 4.44
-1 to 70 4.22
-1 to 200 4.07