G-TRAN Series Multi Ionization Gauge ST2-1 / ST2-2

Don’t you have a problem with the precision of the vacuum gauge (Variation of sensitivity, error, etc.) and short life (gauge head becomes dirty and it is hard to discharge, etc)in measurement at high vacuum ?
To respond to such requests, ULVAC has developed an ionization vacuum gauge with a spec of long-life at severe environment and a measurable type with high precision.
This world’s first metal type triode ionization vacuum gauge is greatly reduce the running cost and help further improving the yield of various processes.

◙ World’s first metal type triode ionization vacuum gauge (Patent pending)
Even in harsh environment, this world’s first metal type triode ionization vacuum gauge will achieve long-life and shows the best advantage of the triode type.
◙ Strong Metal Vacuum Tube
robe is made of small metal which makes no worry of such damage as glass type.
◙ Improvement in the measurement accuracy
Improvement in the measurement accuracy of ±10% and excellent sensitivity stability has realized.
◙ Wide-range measurement
Wide pressure measuring range from atmospheric pressure to high vacuum range (10+5 to 10-5Pa, 760 to 7.75×10-8 Torr, 1013 to 10-7mbar).(When SPU and SAU are used together)
◙ Possible to connect gauge heads with different measurement ranges
With Multi Ionization Gauge, a gauge head is selected depending on the usage
◙ Precise measurement of atmospheric pressure
Confirming atmospheric pressure easily and accurately (when SAU is used together)
◙ Indication signal of filament life time by the electron
Monitoring the electron volume can observe the life time of filament.
◙ Low environmental burden
Capable of reducing costs as only failed gauge heads are replaced
◙ Improvement in visibility
With high visible LED for error verification
◙ Maintenance
Easy sensor head replacement
◙ Applicable standard
Conforms with CE
◙ Process control in high vacuum process such as for OLED and Touch panel manufacturing system.
◙ Measurement of ultimate pressure at various industrial vacuum equipment such as vacuum furnaces.
◙ Measurement under atmosphere which include hydrocarbon (oil-based).
◙ When processing of vacuum parts, measurement under atmosphere where oil and lavage remain potentially.
◙ Measurement of vacuum equipments that wants to aim at exchange frequency reduction of sensor head.
※Please contact in case of using Corrosive gas (Halogen gas).
Model ST2-1 ST2-2
Type name Standard type Serial communication type
Connectable sensors ST2 gauge head SWT-16 (NW16): 1
SPU Pirani vacuum gauge measuring unit: 1 (option)
SAU pressure sensor unit: 1 (option)
Measurable pressure range 1×10-5 to 1×10+1 Pa
Accuracy 1×10-4 to 3 Pa: ±10%
7.5×10-7 to 2.2×10-2 Torr: ±10%
1×10-6 to 3×10-2 mbar: ±10%
Repeatability 1×10-4 to 3 Pa : ±2%
Sampling time 50 ms, 5x moving average
Value output Output voltage: 0 to 10 VDC, LOG output: 0.75 V/1 decade
Pressure conversion equation: V=7.25+0.75* (LogP-2)  P=10^{ (V-7.25)/0.75+2}*Also combined with the output voltage for setpoint adjustment (SH2-1 only)
Update time 50ms
Control input signals FIL ON/OFF, FIL 1/2, DEGAS ON/OFF
Operates with open collector input, negative logic
Control output signals Sensor error, setpoint 1/2/3, emission valid,
filament current abnormality
Rating: 24VMAX, 50mAMAX, saturation voltage 1V
Serial communications RS232C、RS-485
LED display POWER/ERROR: Power, error LED
FIL: B-A gauge filament status indicator
SET1 to 3 Setpoint 1 to 3 LED
Emission current 2mA (1×10-2 Pa or lower), 10μA
Degas Method Electron bombardment – Emission current 2mA, grid voltage approx. 330V
Maximum pressure of
B-A: 2×10+5 Pa (absolute pressure) * Take the withstand pressure for flanges, clamps, and other components into account separately.
Internal volume of sensor SWT-16: 17cm3
Operating temperature range 10 to 50℃
Operating humidity range 15 to 80%  RH (no condensation)
Storage temperature -20 to 65℃ (when unpowered, no condensation)
IP rating IP30
Power supply voltage 20 to 28 VDC (ripple, noise 1% or lower)
Steady state 8W, Degas 19W or lower, 6A or lower when power supply turned on (4m)
Input/output connector D-sub15-pin 2.6mm screws
Weight Controller: Approx. 530g, Gauge head (SWT-16) 80g
Dimension 183.8×75×62.2mm
Applicable standard CE standards
Options Multi Ionization
Sensor head
SWT-16 (NW16)  material of gas contacting sections: Filament: Ir/Y2O3 -coated
PtC-Mo, SUS304, W, Kovar glass, Kovar/Ni plating
Pirani Vacuum Gauge SPU
Pirani Vacuum Sensor head WP-16 (NW16)
Material of gas contacting sections: Filament-Pt, BS/Ni plating, Ni, solder
Pressure sensor SAU (NW16) Material of gas contacting sections: SUS316L
Unit cable 0.5m for SPU/0.5m for SAU
Display unit 1CH: ISG1 (DC24V)
4CH: IM1R1 (DC24V)/IM2R1 (AC100V)
Display cable Cable between ST2 and display unit
2m, 5m, 10m, 15m, 20
Input/output conector (D-sub 15-socket (M2.6mm screw))
Inspection result data sheet, General calibration test report, JCSS caribration certificate


>> Mode Specifications

ST2 have three options; simple mode with a multi ionization gauge, combination mode with a multi ionization gauge and a pirani gauge (SPU), and triple combination mode with a multi ionization gauge, a pirani gauge (SPU) and a pressure switch.

Mode ST2
Simple mode
Combination mode
Triple combination mode
pressure range
1×10-5 ~ 1×10+1Pa 1×10-5 ~ 1×10+4Pa  1×10-5 ~ 1×10+5Pa
Accuracy 1×10-4 to 3Pa : ±10%
3 to 1×10+1Pa : ±15%7.5×10-7 to 2.2×10-2 Torr: ±10%
2.2×10-2 to 7.5×10-2 Torr: ±15%1×10-6 to 3×10-2 mbar: ±10%
3×10-2 to 0.1 mbar: ±15%
1×10-4 to 3Pa : ±10%
3 to 1×10+3Pa : ±15%
1.0×10+3 to 3.0×10+3Pa : ±30%7.5×10-7 to 2.2 10-2 Torr: ±10%
2.2×10-2 to 7.5 Torr: ±15%
7.5 to 22.5 Torr: ±30%1×10-6 to 3×10-2 mbar: ±10%
3×10-2 to 10 mbar: ±15%
10 to 30 mbar: ±30%
1×10-4 to 3Pa : ±10%
3 to 1×10+3Pa : ±15%
1.0×10+3 to3.0×10+3Pa : ±30%
1.0×10+4 to 1.0×10+5Pa : ±3%F.S.7.5×10-7 to 2.2 10-2 Torr: ±10%
2.2×10-2 to 7.5 Torr: ±15%
7.5 to 22.5 Torr: ±30%
75 to 760 Torr: ±3% F.S.1×10-6 to 3×10-2 mbar: ±10%
3×10-2 to 10 mbar: ±15%
10 to 30 mbar: ±30%
100 to 1013 mbar: ±3% F.S.
Repeatability 1×10-4 ~ 3Pa : ±2%

▇ Secret of strength of the ST2 ▇