Humidity, dust, and wind limits

Always monitor the current weather on the MET station in the control room.

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If >90% humidity outside, close dome and wait until <80% or conditions seem stable. If in doubt contact the INT Telescope Operator (telephone 640).

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Wind speed limit for JKT is 50km/hr (steady, not gusts). Close the dome if this limit is exceeded. If concerned, check with the INT Telescope Operator (telephone 640).

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If the air is very dusty outside, the telescopes will not be opened. Keep in touch with the Telescope operators on the INT (telephone 640) and WHT (telephone 559) about this.

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If >50% humidity in dome, turn on dry N2 to first `notch'. The flow is controlled by the flow valve hanging around the mirror cell, and should be adjusted to deliver 100 l/hr. This to make sure that the CCD-window will stay free of condensation.

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If the humidity is high or if it is very dusty outside, please turn off the dome fans with the four switches in the control room.

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If it is wet and stormy, position the the dome with the shutter into the wind.

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If it is wet and very cold, position the dome such that the shutter is facing south. In case the dome freezes up, the Sun will get a chance to heat up the shutter.

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Please read the instructions accompanying the new met station, to the right of the control desk, particularly with respect to the alarms. The alarms sound if the above environmental thresholds are transgressed, or the dew-point falls to less than two degrees.