Chemical analysis probes, such as pH probes, ion-specific electrodes and fiber optic probes, are widely used to chemically analyze samples, usually liquid samples contained in a sample vessel. When the probe is a fiber optic probe, light can be directed down a fiber optic cable to the fiber optic probe, is then directed through the sample to a mirror, then bounces off of the mirror back through the sample and then back up another fiber optic cable to a photometer. The sample absorbs a portion of the light so directed through it and this absorption is measured to analyze the sample.
The probe is generally supported and positioned by apparatus which allows the immersion of the probe into the sample where it is held during the analysis. Then, generally, the probe is removed from the sample and any residual sample remaining on the probe is washed away with a suitable liquid. In the case of a fiber optic probe the wash liquid is frequently a volatile liquid. Generally, the probe is supported and positioned by an arm vertically movable along a vertical column or by an arm comprising link members which provide for horizontal as well as vertical movement. When chemical analysis probes are used for routine analyses by unskilled persons (such as by an industrial worker who may be more used to operating rugged process valves than more fragile laboratory equipment), the known probe supports either provide too little freedom of movement of the probe or too much. Care is needed to guide the probe into the sample (generally a two-handed operation) without bumping the probe or probe arm into the sample vessel with the possibility for breaking the probe and/or the vessel. In addition, contamination of the sample can be a problem if a washed probe is used for another analysis before the wash liquid has completely evaporated.