,

As part of the salt load control system, LMBV mbH operates an extensive measuring and control network of numerous receiving water measuring points in Bode and Wipper for monitoring the chloid concentration in the southern Harz (lot 1). In addition, LMBV mbH operates underground and tunnel measuring points for monitoring chloride concentrations and runoff in the Sangerhäuser and Mansfeld copper shale district (Lot 2). The location of the measuring points is shown in the following table. In addition, LMBV mbH operates a measuring center in which the data of all stations are merged.

,

The scope of this tender is the execution of the repeated maintenance of each measuring point as well as the measuring center including fault suppression work in accordance with the service description. In addition, scientific and metrological

Consulting services on all aspects of the overall system Are part of this tender, which are requested by the client as required.

,

,

This call for tenders shall comprise:

• in lot 1 all maintenance and, if necessary, fault suppression work for the transmission and measuring stations "Salt Load",

• in lot 2 all maintenance and, if necessary, fault clearance work for the measuring stations "Stollen" and "Underground" and

• in lot 3 all maintenance and, if necessary, fault suppression work for the measuring centre as well as

• in lot 4 hourly wage work at the request of the client.

,

The stations are to be maintained in the following cycle:

• Lot 1: 3x annually in April, August and December. It is possible to move the date to the previous or following month, provided that the interval between 2 maintenance dates is at least 3 months and not more than 5 months.

• Lot 2: 2x per year, in the first half of the year and in the 2nd half of the year. The interval between 2 maintenance dates must be at least 4 months and must not exceed 8 months.

• The dates must be chosen in such a way that the discharge measurements at one station are always carried out in a different month until a discharge measurement has been carried out in each month. After that, this procedure must be started all over again.

In the case of stations that are not accessible to the public, it is the contractor's responsibility to ensure that the stations are accessible on the planned maintenance date. The maintenance dates must be communicated and agreed to the customer no later than 14 days in advance.

,

In general, in the course of regular maintenance on the in 2.2. maintenance dates to maintain the devices listed in 2.1 according to the manufacturer's specifications. In particular, warning and error messages of the devices (if applicable) must be recorded and logged.

In particular, the following steps must be carried out:

• Visual and functional control of solar modules, control cabinet, conduits

• Visual and functional control of mechanical measuring devices (in particular swivel arm, pipe system, measuring channel) and compressed air flushing

• Cleaning of mechanical measuring devices (in particular measuring cage and connecting pipe to the maintenance shaft) and compressed air flushing

• Visual and functional control of the other devices (in particular BW2: function control leakage alarm)

• Reading of the warning and error messages of the devices (if applicable)

• Cleaning of all sensors

• Control measurements according to 2.4

• Calibration and validation work according to 2.5

• Battery management according to 2.6

• Exchange of desiccant with regenerated desiccant, regeneration of the replaced desiccant

• Preparation of a maintenance protocol

,

The following control measurements and control readings shall be carried out during each maintenance. For each control measurement / control reading, the corresponding measured value of the station must be determined. The results of the control measurements and control readings shall be documented in the maintenance protocol:

• For stations with conductivity and temperature measurement: control measurement conductivity and (water) temperature with a calibrated measuring instrument to be provided by the contractor before the start and after completion of the maintenance work (lot1: 14 measuring points, lot2: 6 measuring points)

• At station BW1: Control measurement air-temperature with a calibrated measuring instrument to be provided by the contractor before the start and after completion of the maintenance work (lot1: 2 measuring points, lot2: 0 measuring points)

• For stations with a slatted level of the TLUBN or with a slatted level of the client or with a control scale: reading of the slatted level or the control scale (lot1: 7 measuring points, lot2: 4 measuring points)

In addition, for stations with a slatted level of the TLUBN (MW5, MW7 and MB4), the water levels measured at the stations must be compared with the water levels registered by the TLUBN at least twice a week (Mon+Thu, Mon+Fri or Tue+Fri) with the water levels registered by the TLUBN (Lot1: 3 measuring points, Lot2: 0 measuring points). In the case of deviations of more than +- 2cm in the moving weekly average, the offset of the respective level measurement must be adjusted.

,