Frequently Asked Questions

Yes, but the response time is likely to be adversely affected. Filter chemistry may affect response to certain gases. Contact SGX  for advice.

This depends on the level and duration. The longer and higher the concentration, the greater the degree of zero drift and change in (net) sensitivity. The latter is usually a decrease in sensitivity.

The MPEL is certified ExIa, all other pellistors do not have an intrinsic safety approval.

Some pellistors sensors do have safety approvals. Refer to datasheets and/or Approval Certificates.

More than 12% oxygen needs to be present in the sample stream.

The time period between calibration will be dependant upon the environment in which the sensor will be operating and the required accuracy. A three month calibration period for sensors operating in “normal” conditions could be used. For environments where poisons or inhibitors are likely to be present, the instruments should ideally be “bump tested” before every use, to ensure the sensor has not become poisoned.

See Pellistor Application Note 6

Some sensor to sensor variation is observed from the theoretical response (see Pellistor Application Note 3 and the datasheet). Ideally the sensor should be calibrated to the actual target gas or vapour.

Sensors are not sensitive to storage temperature. See individual datasheets.

Data is available for some gases vapours. Theoretical data is available in the Pellistor Application Notes.

The letters in the serial number depict the date of manufacture. Where displayed this date code will record the month / year of manufacture.

Some decrease in response time may be seen, care must be taken not to pressurise the sensor which may give elevated responses.

Larger than normal changes to the sensor zero and sensitivity to the target gas will be seen.

The sensor temperature will begin to equilibrate to that of the gas. Changes in the zero and sensitivity to the target gas may be seen.

The sensor temperature will begin to equilibrate to that of the gas. Changes in the zero and sensitivity to the target gas may be seen.

Certified housings are made mostly from stainless steel.

Stable sensor performance relies in part to diffusion control. A minimum gas flow is required to replace gas reacted by the sensor.

See individual datasheets. The sensors are run in a Wheatstone bridge circuit either in constant voltage or current mode.

Typically, Pellistors can be stored for up to 12 months.

For VQ500 series sensors please use sockets shown here For other pellistors connect to header legs by soldering or mechanical methods.

All sensors will show a change in sensitivity (and in some cases zero) with temperature.  For more specific information please refer to the relevant datasheet and application note.

A membrane filter is useful to help protect the sensor from ingress of dirt and liquids, which can upset the IR optical cavity. The filter cover will also slow the response of the sensor, depending on the porosity of the filter material.

All Infrared gas sensors can withstand exposure to target gas for long periods.

Certain types are Intrinsically Safe for mining (methane only). Refer to Datasheets for more information.

Some infrared sensors do have safety approvals. Refer to datasheets and/or Approval Certificates.

None.

The time period between calibration will be dependant upon the environment in which the sensor will be operating and the required accuracy. Typically, a six month recalibration period would be used.

None, although care must be taken to ensure the sinter does not get blocked with any particulates.

This is due to increasing pressure causing an increase in gas density.

Sensors are not sensitive to storage temperature. See individual datasheets.

Please contact SGX or consult datasheet.

The letters in the serial number depict the date of manufacture. Where displayed this date code will record the Year / Month of manufacture in the form of two letters.

A pump will not affect the response time of the sensor itself, provided it does not create a pressure differential between the outside and inside of the sensor.

IR Gas sensors are not damaged by pressures outside the quoted range, but their signal response will not be linear with gas concentration, unless a special correction algorithm is used – contact SGX gas sensor engineering.

The sensor and gas inside the sensor will equilibrate to the surrounding temperature. Care will need to be taken to ensure condensation does not form inside the sensor, during any temperature changes.

All IR sensors are made in stainless steel

No, the sensor works by diffusion. No gas is consumed during exposure to the sensor.

See Datasheets.

Unlimited.

See datasheets for pin out connections. Check here for recommended sockets 

All sensors will show a change in sensitivity (and in some cases zero) with temperature.  For more specific information please refer to the relevant datasheet and application note.

Yes, but the response time is likely to be adversely affected. Filter chemistry may affect response to certain gases. Contact SGX for advice.

This depends on the level and duration. The longer and higher the concentration, the greater the degree of zero drift and change in (net) sensitivity. The latter is usually a decrease in sensitivity.

Refer to the Electrochemical Application Notes

No.

Sensor will work for at least 24 hrs in 0% O2-otherwise at least several thousand ppm O2 required

The time period between calibration will be dependant upon the environment in which the sensor will be operating and the required accuracy. Typically, a three to six month recalibration period would be used.

Exposure to high concentrations of solvents such as Acetone can affect the electrodes within the sensor.

Sensors are not sensitive to storage in normal temperatures-however prolonged exposure to high temperatures should be avoided.

Please contact SGX or consult datasheet.

The letters in the serial number depict the date of manufacture. Where displayed this date code will record the Year / Month of manufacture in the form of two letters.

Some decrease in response time may be seen, care must be taken not to pressurise the sensor which may give elevated responses.

Larger than normal changes to the sensor zero and sensitivity to the target gas will be seen.

The sensor temperature will begin to equilibrate to that of the gas. Changes in the zero and sensitivity to the target gas may be seen.

Stable sensor performance relies in part to diffusion control. A minimum gas flow is required to replace gas reacted by the sensor.

Sensors work in a potentiostatic circuit which requires very low power (see Electrochemical Sensors Application Notes 2 and 5).

Refer to Datasheets.

See datasheets for pin out connections.

All sensors will show a change in sensitivity (and in some cases zero) with temperature.  For more specific information please refer to the relevant datasheet and application note.

Yes, but the response time is likely to be adversely affected. Filter chemistry may affect response to certain gases. Contact SGX for advice.

This depends on the level and duration. The longer and higher the concentration, the greater the degree of zero drift and change in (net) sensitivity. The latter is usually a decrease in sensitivity.

No.

No.

More than 12% oxygen needs to be present in the sample stream.

The time period between calibration will be dependant upon the environment in which the sensor will be operating and the required accuracy. A three month calibration period for sensors operating in “normal” conditions could be used. For environments where poisons or inhibitors are likely to be present, the instruments should ideally be “bump tested” before every use, to ensure the sensor has not become poisoned.

The sensors can be affected by exposures to organic silicon compounds and cfc’s. Contact SGX for further advice.

Sensors are not sensitive to storage temperature. See individual datasheets.

Please contact SGX or consult datasheet.

The response time maybe reduced, but care is needed not to change the sensor operating temperature.

Larger than normal changes to the sensor zero and sensitivity to the target gas will be seen.

The sensor temperature will begin to equilibrate to that of the gas. Changes in the zero and sensitivity to the target gas may be seen.

Stable sensor performance relies in part to diffusion control. A minimum gas flow is required to replace gas reacted by the sensor.

See individual datasheets. The sensors are run in a simple circuit at constant voltage.

Typically, Pellistors can be stored for up to 12 months.

For TO39 sensors use sockets or solder to board. For SMD solder direct to board.

Yes the module can be configured with different I2C-adresses. But in current Software revision it needs to be done with the programmer.  Please contact with us and tell which addresses are suitable for you. We will be preparing for you the new address.

The I2C speed grades (standard mode: 100 kbit/s, full speed: 400 kbit/s, fast mode: 1 mbit/s, high speed: 3,2 Mbit/s) are maximum ratings. Compliant hardware guaranties that it can handle transmission speed up to the maximum clock rate specified by the mode.  For our design, we choose the standard-mode (100kbits/s max)… It means that the I2C-master should not communicate with the module faster.