This invention concerns a fluorometer preferably combined with a thermal cycler useful in biochemical protocols such as polymerase chain reaction and DNA melting curve analysis. During execution of the over-steer suppression control, the braking force for suppressing front-wheel idle rotation to be imparted to the front wheel located on the inner side of the turning locus by means of the front-wheel-side LSD control is lowered, whereby the rear wheels become unlikely to produce excessive idle rotation. Filtration of undesirable low energy radiation may be employed using an attached filter element. The tank can be applied to electrical apparatus like transformers, autotransformers, and reactors and the like. The spring is configured to bias the valve member toward the valve seat, wherein the spring engages a portion of the stem while the poppet is in the deflating position.