Abstract: The present invention relates to a chemical compound that has applications as a luminescent indicator dye, and to an optical sensor, typically employed for determination of near-neutral pH values of aqueous samples. The optical sensor has particular application in the pH determination of body liquids such as, for example, blood, plasma and serum.

Abstract: An apparatus which permits continuous automatic determination of the bulk specific gravity of a powdery sample and highly precise measurement thereof. The apparatus comprises a robot 3 transporting a container 2 filled with a powdery sample; a funnel 4 provided with a damper, which receives the powdery sample discharged from the container 2; a damper-driving unit 5a for pulling out and pushing the damper 5; a sample sensor 7 for detecting the powdery sample dropped through the funnel 4 provided with a damper; a constant volume receiver 6 for receiving dropped through the funnel 4 provided with a damper; a scraping bar 8 for sliding the upper face of the constant volume receiver 6; a scraping bar-driving unit 8a for reciprocating the scraping bar 8; a constant volume receiver-conveying robot 21 transporting the constant volume receiver 6; an electronic balance 22 which determines the weight the powdery sample in the constant volume receiver 6; and a cleaner 23 for aspirating the weighed powdery sample.

Abstract: The measuring device has bobs 10, 17 suspended from a weight 12 with wires 11, 16. The hook 13 of the weight 12 is hung from a suspensor thread 15 extending downwards from a balance 14. The weight 12 may be omitted by using the upper bob 10 for dead weight. The bobs 10, 17 and the wires 11, 16 may be coated with a coating layer unreactive to the melt 19 whose density is to be measured. The weights of the measuring device is measured by the balance 14 under the first condition that the lower bob 17 is immersed in the liquid 19 and the second condition that the bobs 10, 17 are both immersed in the liquid 19. The density of the liquid 19 is calculated from the two measured values without the influence of the surface tension of the liquid 19 applied to the wires 11, 16.