Abstract: A chemical fluid for underground injection includes an inorganic substance, an antioxidant (e.g. ascorbic acid, gluconic acid, or a salt thereof, or ?-acetyl-?-butyrolactone, or bisulfite, or disulfite), and water. The inorganic substance may be a colloidal particle or a powder. The inorganic substance may be present in the chemical fluid in amounts of 0.001% by mass to 50% by mass based on the total mass of the chemical fluid for underground injection. The antioxidant may be present in the chemical fluid at a ratio of 0.0001 to 2 of the mass of the antioxidant to the mass of the inorganic substance. A surface of the inorganic substance may be coated with a silane compound. The chemical fluid may further include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or a mixture thereof.

Abstract: A multi-range timer comprising an RC oscillator with a variable resistor whose resistance is varied with rotation of a dial. A fixed frequency divider circuit frequency-divides the output of the RC oscillator. A variable frequency divider circuit receives an output of the fixed frequency divider circuit, and a time setting section having a digital switch switches a frequency division ratio of the variable frequency divider circuit. The time limit is changed by switching the digital switch. The time setting section comprises a dial and a plurality of numerical value scales distinguished from one another by color, each of said scales having the same color as the display surface of said digital switch, which indicates a selected time setting range.