Abstract: Gas detection devices comprise a dehydration unit a concentration unit, and a temperature control unit for controlling a temperature. The gas detection device includes a sampling mode in which sample gas flows into and out of the dehydration unit through a first port and a second port, respectively, wherein the volatile organic compounds in the sample gas are concentrated in the concentration unit. The temperature control unit may be configured such that the temperature of the sample gas after flowing out from the dehydration unit and before flowing into the concentration unit is not greater than a first preset temperature. Generation of condensed substances in the sample gas can be effectively avoided in a simple manner after the sample gas flows into the concentration unit, thereby further preventing ice blockage. Methods for detecting volatile organic compounds in a sample gas are also disclosed.

Abstract: A strap connector for coupling with a lawn cutting device and permitting a strap connected to the strap connector with more freedom of movements, the strap connector includes a first coupling device statistically connected to a portion of a shaft of the lawn cutting device, a second coupling device connected to the first coupling device in a relative rotation relation, the second coupling device having a first engaging portion surrounding the first coupling device and a second engaging portion extending radially from the first engaging portion and having a compartment defined internally, and a ring shaped member having a ring shaped portion adapted for connection of the strap and a connecting portion connected to the second engaging portion of the second coupling device in a relative rotation relation, and the connecting portion received in the compartment.

Abstract: An electric mowing machine includes a stem, a power supply disposed on the stem, a motor base that is installed to the stem receiving a motor which electrically communicates with the power supply and includes a shaft disposed through the motor. A cutter installed on the shaft of the motor rotatably, and a motor secure device mounted between the cutter and the shaft of the motor and adapted for prevent the shaft of the motor from bearing external force.