Boutilier R G, Randall D J, Shelton G, Toews D P
Respir Physiol. 1978 Mar;32(3):381-8. doi: 10.1016/0034-5687(78)90125-1.
Radiometer carbon dioxide electrodes and probably other electrodes of similar design do not give the same readings, except under certain very limited conditions, when used to measure carbon dioxide concentrations in solution and the gas phase with which the liquid is in equilibrium. Blood samples of high P(CO2), when introduced into the sample chamber of an electrode at low P(CO2), lose CO2 to the electrode resulting in a reduction of sample P(CO2) and hence, because the sample size is very small, a recorded value much below the real P(CO2) of the sample is obtained. The reverse occurs if the P(CO2) of the sample is below that of the electrode. To avoid these problems the electrode should be held at the same P(CO2) as the sample, or sample replacement should be used to establish the real P(CO2). The differences in response of the electrode to gases and liquids should also be taken into account.
辐射计二氧化碳电极以及可能其他类似设计的电极，在用于测量溶液中二氧化碳浓度以及与液体处于平衡状态的气相中的二氧化碳浓度时，除了在某些非常有限的条件下，不会给出相同的读数。高P(CO₂)的血样，当被引入到低P(CO₂)的电极样品室中时，会向电极释放二氧化碳，导致样品P(CO₂)降低，因此，由于样品量非常小，会得到一个远低于样品实际P(CO₂)的记录值。如果样品的P(CO₂)低于电极的P(CO₂)，则会出现相反的情况。为避免这些问题，电极应保持与样品相同的P(CO₂)，或者应使用样品置换来确定实际的P(CO₂)。还应考虑电极对气体和液体响应的差异。
