Measuring pressure from atmospheric pressure to high vacuum range by one principle is impossible in today’s technology.
Hence, complex vacuum gauges which have the sensor head with different measurement principles are prevailed. But there are some demerit on the complex vacuum gauges as below;
1. All sensor heads need to be replaced when a sensor head is broken.
2. Easy to break for the complexity of sensor heads
3. Sensor head is expensive

ULVAC adopts the separate sensor head method (patent pending) with its sensor head selectable at customer’s choise. It’s capable of measuring wide range of pressure, lowering runninng cost and stress on emviroment.


  • Wide pressure measuring range from atmospheric pressure to high vacuum range (10+5 to 5×10-8Pa.)(When SPU and SAU are  used together
  • Cost of sensor heads can be cut by multi ionization sensor head method (patent pending )
  • Confirming atmospheric pressure easily and accurately (provide SAU is used)
  • An advance warning will be made before the life of ionization vacuum gauge comes (patent pending)
  • Error verification LED equipped


  • Process control in high vacuum processes such as for photovoltaic field, FPD, semiconductor, optics and electronic parts manufacturing systems.
  • Process control in high vacuum range processes such as for process control for vacuum systems with multiple process chambers, such as in-line sputtering and single wafer processing equipment.
  • For pressure measurement of high vacuum or ultra high vacuum equipment used in UHV research work.


Model SH2-1 SH2-2
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 outpu:t 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 50msec
Control input signals FIL ON/OFF, DEGAS ON/OFF
Operates with open collector input, negative logic
Control output signal Error signal, Setpoint1/2/3, Emission valid
Watch of electric power of filament
Rating : 24VMAX、50mAMAX、Saturation voltage 1V
Serial communication type RS232C/RS-485
LED display POWER/ERROR: Power, ERROR LED (Blinking changes depending on each mode) 
FIL : Emission valid LED
SET1: Setpoint 1 LED
SET2: Setpoint 2 LED
SET3: Setpoint 3 LED
Emission current 1mA(1×10-3Pa or less)、10μA
Degas Method Electron bombard type 1mA, 350V
Maximum pressure of sensor 2×10+5Pa (1.5×10+3 Torr, 2×10+3 mbar) (Absolute pressure) 
*Need separate measures as a capacity to resist pressure, such as flange and clamp
Internal volume of sensor 17cm3(M-34), 19cm3(M-35), 17cm3(M-36)
Operating temperature range 10 to 50?C (50 to 122?F)
Operating humidity range 15 to 80% (not condensing)
Storage temperature -20 to 65?C (-4 to 149?F) (At non-energizing, not condensing)
IP rating IP30
Power supply voltage DC20 to 28V (Ripple, Noise 1% or less)
Steady state 8W, Degas 19W or lower, 6A or lower when power supply turned on (4ms)
Input/output connector D-sub15-pin (M2.6 screw)
Weight Sensor unit : 530g, B-A sensor gauge (M-34/35) : 80g, (M-36) : 300g
Dimension W×D×H 144mm×75mm×62mm以下(Power supply)
Applicable standard CE
Option Multi Ionization Sensor head M-34(NW16)、M-35(NW25)、M-36(ICF070)
Material of gas contacting sections :: 1-filament・Ir/Y2O3, 2-filament・W, Another-PtC・Mo, SUS, W
Pirani Vacuum Gauge SPU
Pirani Vacuum Sensor head WP-16(NW16)
Material of gas contacting sections : Filament-Pt, Another-BS/Ni Plating, Ni, Solder
Pressure switch SAU(NW16) Material of gas contacting sections : SUS316L
Unit cable 0.5m、1m、2m for SPU,0.5m、1m、2m for SAU
Display unit 1CH:Model ISG1 (DC24V) 
4CH *1: Model IM1R1 (DC24V), Model IM2R1 (AC100V)< /td>
Display cable Cable between SH2 and Display unit
Certification Document Inspection result data sheet, General calibration test report,
JCSS calibration certification

*1 Non available for combination mode


SH2-1/SH2-2 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 SH2-1/SH2-2
Simple mode
Combination mode
Triple combination mode
Measurable pressure range 5×10-8 to 1×10+1Pa 5×10-8 to 1×10+4Pa 5×10-8 to 1×10+5Pa
Accuracy 5×10-8~1×10+1Pa:
1.0×10+3~3.0×10+3Pa: ±30%
No warranty
1.0×10+3~3.0×10+3Pa: ±30%
No warranty
1.0×10+4~1.0×10+5Pa: ±3%F.S.
Repeatability 1×10-6~1×10-1Pa: ±2%
Connection diagram (for Example) SH2-1.jpg SH2-2.jpg SH2-3.jpg



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