CPC G01N 33/0045 (2013.01) [G01N 33/0073 (2013.01)] | 14 Claims |
1. A sensor, comprising:
a handhole part including an inner wall;
a sensor module provided in the handhole part, the sensor module including
a housing,
a sensor circuit provided in the housing, the sensor circuit including a gas sensor element, and
a battery configured to supply electrical power to the sensor circuit; and
a holder holding the sensor module so that a gap is formed between the inner wall and the housing and between the housing and a first member,
wherein:
the housing includes a lower part facing the first member,
the lower part includes a hole through which a gas can pass,
the holder is tubular,
an opening at a lower end portion of the holder faces the first member,
an opening at an upper end portion of the holder faces the hole, and
a cross-sectional area of the opening at the lower end portion is greater than a cross-sectional area of the opening at the upper end portion.
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