Abstract: A method and device for detecting urea are provided. The method for detecting urea includes the following steps. A derivatization reagent reacts with a sample to obtain a mixture, wherein a reaction time period for reacting urea in the sample with the derivatization reagent to form a derivative product is controlled. The derivative product is separated from the mixture. The amount of separated derivative product is analyzed to determine the concentration of urea in the sample.

Abstract: An elevating work platform structure for use in constructing an elevator channel before and after the elevator car has been placed into the elevator channel includes a horizontal beam, two side posts connected to two ends of the horizontal beam, two upper platforms integrally connected to two upper side ends of the two side posts respectively, two lower platforms integrally connected to two lower side ends of the two side posts respectively, and two safety brake arrangements provided at a lower front portion of each of the side posts for providing an instant emergency brake if the suspension cable holding up said elevating work platform structure breaks.

Abstract: A breaking arrangement for elevating work platform includes a break body, a C-shaped receiving piece, a breaking unit, and a break released handle. The breaking arrangement allows only upward movement of the elevating work platform during normal operation, the construction workers can move downward after a break released handle is released. The breaking arrangement can further provided an emergency stop when failure occur in the main suspension cable or the winding machine, so that the elevating work platform would not slide down.