The GEMU C31 Hydra-Sensor pressure measurement device is equipped with a pressure transmitter. The body is made from PFA and can be directly integrated into the pipe system by commom flare unions. A PFA double diaphragm prevents contamination of the working medium. Only the PFA body and the PFA diaphragm are wetted parts. The pressure is transmitted by a monitor liquid (50 % DI water and 50% IPA (isopropyl alcohol) or 100 % Dl water).

  • C31 is especially suitable for pressure measurement of ultra high purity chemicals
  • All wetted parts are made from High Purity PFA
  • Pressure transmission by double diaphragm technology
  • Pressure transmitter can be rotated through 360°
  • Minimal deadleg
  • The proven GEMU CleanStar® technology is the basis of the transmitter
  • Working medium isolated from the transmitter by a patented PFA double diaphragm
  • Pressure transmitter can be positioned through 360° enabling individual user options


Type C31
Nominal Size 1 1/4" DN 25 1" DN 20 1/2" DN 10 1/4" DN 4 1/4" NPT DN 4 3/4" DN 15 3/8" DN 6
Mounting Variant Dead-End In-Line
Connection Flare connection with PFA union nut Flare connection with PVDF union nut NPT female thread
Body Material PFA
Diaphragm Material PFA
Units Bar kPa psi
Measuring Range 0...100 psi, 0...600 kPa, 0...6.0 bar 0...30 psi, 0...250 kPa, 0...2.5 bar 0...60 psi, 0...400 kPa, 0...4.0 bar -30 inHg...15 psi, -100...150 kPa, -1...1.5 bar -30 inHg...30 psi, -100...300 kPa, -1...3.0 bar -30 inHg...60 psi, -100...500 kPa, -1...5.0 bar
Electrical Connection Cable outlet, IP 67, 5.0 m flying lead (Housing Epoxy coated) L-plug DIN 43 650, IP 65
Display LCD, 4-digit Without
Fill Fluid of Transmitter DI water Isopropyl alcohol (IPA) / DI water 50:50
Transmitter Version High Purity, White


Version of Transmitter Diaphragm Double diaphragm system for overpressure ranges, Single diaphragm for ± pressure ranges.
Material of Wetted Parts PFA
Flow Medium Suitable for any inert or corrosive gases or liquids, - particulary high purity media - which do not corrode the body and diaphragm materials. For corrosive media like HCL type C32 is recommended
Flow Direction Optional

Pressure Transmitter

Auxiliary Power DC 10...30V
Output Signal 4...20 mA, two wire
Cable Length 5 m, with cable outlet IP 67
Characteristic Deviation 0.5 % of span
Voltage Drop 3 V
Pressure Measurement Device Sensor 4...20 mA, 2-wire system (with optional pluggable LCD)
Max. Admissible Current 40 mA
Temperature Compensation Additional measurement error up to 0.5 % per 10° C temperature deviation from the reference temperature of 20° C