Maintenance - Van Walt Rain Gauge Operating Instructions Manual

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VAN WALT

Monitoring your needs

The datalogger produces incorrect measurements. The fault is in the sensor or the datalogger.

• Check the mechanical parts and the state of maintenance of the sensor, proceeding in

accordance with Chapter 7, "Maintenance".

• Check the calibration of the sensor and, if necessary, recalibrate according to the relevant

instructions in Chapter 7, "Maintenance".

• Check the Offset and Range settings of the datalogger and, if necessary, reset them.

The Offset and Range settings are part of the sensor calibration. Consult Chapter 7,

"Maintenance," to correctly determine the values for Offset and Range.

The alarm of the sensor is not functioning or not functioning correctly.

• The alarm function is only supported by e-SENSE direct or the e-SENSE data site.

• If no alarm messages are received: check the settings for Alarm low, Hysteresis low, Hysteresis

high and Alarm high. Configure the alarm values if one or more settings are set on zero.

• If an alarm message is received once but not after that: the value for Hysteresis high should

be set lower than Alarm high, the value for Hysteresis low should be set higher than Alarm low.

If the problem persists, choose both hysteresis values in such a way that they approximate the

alarm values better.

• If many alarm messages are received repeatedly: choose the hysteresis values in such a

way that the difference with the alarm values is increased. If the problem persists, check the

course of the measurements and set a higher Sample speed if the measurements are widely

dispersed.

Maintenance

Reliable and accurate measuring results can only be achieved with regular maintenance. We

recommend you inspect the rain gauge at set times and, if necessary, clean it or repair it in the

following areas:

• Regularly inspect the water-collecting basin and the filter for dirt, damage or blockages. It

should be noted that during certain periods of the year, leaves, dust and dirt tend to collect

in the water-collecting basin and filter. Leaves can simply be removed, while the filter may be

cleaned after removing the cover and then the filter. Clean the filter and reassemble in reverse

order.

• Regularly inspect the tipping bucket for any dirt. Clean if necessary. When doing this, ensure

that the switch is not operated if the datalogger is turned on.

• If at certain times the datalogger is turned off, or if the rain gauge is temporarily out of use

for other reasons, take this opportunity to check the hinge point of the tipping bucket. If it is

possible to move the tipping bucket to the centre position without it getting off balance, the

hinge point must be cleaned thoroughly.

• Check the horizontal position of the instrument every time maintenance is carried out. Despite

the solid design of the field support, in practice the rain gauge can loose its balance as a result

of ground motion, vandalism or rough handling.

Operating Instructions

Rain Gauge

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