UNISENSE H2 Hydrogen Sensors User Guide

June 3, 2024
UNISENSE

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UNISENSE H2 Hydrogen Sensors LOGO**

UNISENSE H2 Hydrogen Sensors

UNISENSE H2 Hydrogen Sensors PRODUCTImportant! Test sensor upon receipt!
This sensor has been successfully tested prior to shipping, however some sensors suffer from rough transportation. Therefore, it is important that you test the sensor upon arrival.

Replacement of defective sensors

Unisense will replace the sensor if it does not meet the specifications below, provided that:

  1.  A test is performed upon receipt without breaking the seal (Note! No seal on MR-sensors for testing purposes)
  2. The complaint is given to Unisense within two weeks from receipt of the equipment.

Guaranteed lifetime

Unisense guarantees the hydrogen sensor a minimum lifetime of 3 months on condition of correct storage and use according to the manual.
Individual sensor calibration is Required
Our sensors are handmade and as the sensor signal relies on the exact geometry of the sensor tip (micrometer scale), some variation must be expected.
Signal amplification
Unisense hydrogen sensors should be connected to a Unisense amplifier such as a UniAmp series instrument or the Field Microsensor Multimeter
Standard hydrogen sensors are functioning correctly if (at Room temperature):

  • It has an immediate response when exposing the tip to hydrogen
  •  The 90 % response time is within the specified range (see table below)
  • The zero signal is less than the specified value (see table below)

| H 2 -10| H 2 -25| H 2 -50| H 2 -100| H 2 -500| H 2 -N| H 2 -NP| H 2 -MR| H 2 -500LR| H 2 -NPLR
---|---|---|---|---|---|---|---|---|---|---
90 % response time (in sec.)| <15| <15| <15| <15| <15| <15| <15| <15| <15| <15
Zero- signal less than| 10 mV| 10 mV| 10 mV| 10 mV| 10 mV| 10 mV| 10 mV| 10 mV| 10 mV| 10 mV

  • The sensor signal in pA is converted to an instrument signal in mV. The default setting of this Pre-Amp range is 1 pA = 1 mV. However, this can be changed by the user (see the instrument manual).

Unpacking

  • Remove the grey shock-absorbing plastic net and inspect the sensor visually.
    Leave the sensor in the protection tube for testing.
connect the sensor to the amplifier
  •  The amplifier is automatically set up correctly when used with these instruments: UniAmp series and Unisense in situ amplifiers.
  • For other amplifiers, set the polarization manually to +100 mV.

NOTE

Incorrect polarization may destroy the sensor
Wait for the sensor to stabilize

  • The signal will be very high right after the sensor is connected and will decrease over time.
  • The period of decreasing signal will normally be at least 1 hour.
  •  Once the signal is stable, calibration can be performed.
  • A typical decrease in sensor signal over time for a sensor that has just been plugged in.
Calibrate the sensor
  • Place the sensor in water or air to obtain a zero H2 calibration point.
  •  Prepare water containing a known concentration of H2 by bubbling a gas with a known H2 content through the CAL300. Place the sensor in the CAL300 to obtain the second calibration point.
  •  Consult the H2 sensor manual for further information about calibrating the H2 sensor.
  • H2 microsensor
  • CAL300 with microsensors  and bubbling  with air.

Approve the sensor

  •  Compare the calibration points to the specifications given on the previ-ous page. If necessary, see Troubleshooting in the H2 Microsensor manual or contact support (see below).

Storage

  • When not in use, store the sensor with the protection tube mounted at 10 – 30°C. If the sensor is used regularly, keep it polarized and connected to the amplifier.

Useful tools

References

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

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