Oxygen sensing OEM modules with high signal output stability and long operational lifetime
Safe supply of gas using gas mixtures different from air is important and in many cases mandatory. In this short newsletter, we will present Pewatron OEM oxygen sensing modules for two important applications, where it is mandatory to measure the oxygen concentration with high precision because of high safety requirements.
Controlled atmosphere (CA) applications, in combination with human activities, are met with some of the highest safety requirements. For instance in fire prevention applications, where the oxygen concentration is lowered to 14-16% or sometime even lower in order to prevent or minimize the risk of fire evolving from power sources coming in contact with explosive gas mixtures. Very often human operating activities by these low levels of oxygen are necessary and the reliable measurement of the oxygen concentration therefore is a critical parameter. For such applications and for most CA applications in general, Pewatron has developed the FCX-MC25-FLOW-CH OEM module. The OEM module has a very stable amperometric zirconia oxygen sensor placed on a control electronics that will output the oxygen concentration with a very high accuracy and the OEM module has an estimated operational lifetime of about 1.000.000 vol% O2 hours. The signal output from the module is very stable over the full lifetime of the module, making the overall cost of operation low.
In oxygen therapeutic applications, high levels of oxygen are administered to patients suffering from for instance lung diseases, and the safety requirements concerning the right dose are immense. There are many therapeutic treatments related to oxygen enriched gas environments, ranging from > 21 Vol% O2 and up to 96 Vol% O2, and in some rare cases up to 100 Vol% O2. For oxygen therapeutic applications and for CA applications with high oxygen levels in general, Pewatron has developed the FCX-MC95-FLOW-CH OEM module. The FCX-MC95-FLOW-CH module has most the same features as the FCX-MC25-FLOW-CH module (zirconia, high accuracy sensor and so on), but very important for the FCX-MC95-FLOW-CH module is the fact that the signal in the upper part of the concentration range is very sensitive to small changes, enabling a very fine control of minimum and maximum concentration for correct dosing.
The two FCX-MC OEM modules are sharing the same electronics platform. The necessary very tight control of the sensor heating is done by the electronics and the signal conditioning and amplification is done using a 12-bit AD converter. Every module is calibrated and checked in more points and the calibration curve is stored in the on-board memory. The customer can easily make small changes to the calibration, for instance if the working point for the customer differ to much in comparison with the conditions during the calibration.