44
b) Calibration of the capillary viscometer with normal oils of the PTB
During this calibration, a normal oil from the PTB with known viscosity is used as a reference measuring
standard. The measurement is performed by means of flow-through measurement of the PTB normal oil
in the viscometer to be inspected in a temperature bath, the temperature of which must correspond
precisely to the test temperature of the PTB. In this case, it is extremely important to make sure that the
temperature is absolutely correct. In case of temperature variation, this will always result in a constant for
the viscometer that deviates from the constant applied. A temperature variation of 0.01 K, for instance,
will result in a measuring error of up to 0.01 %. The calibration of the deviating temperature into the
viscometer constant is not permitted.
c) Inspection by Xylem Analytics Germany with a quality certificate in accordance with
DIN 55 350-18, 4.2.2
The inspection at the manufacturer is carried out by means of comparative measurements using
viscometers as reference measuring standards that were tested at the PTB (corresponds to Item 1).
General Information on the stability of viscometer constants
Each inspection (even with a certificate) can guarantee the technical measuring direction only for a limited
period of time. The constants of viscometers made of the borosilicate glass DURAN
remain unchanged for long periods of time if the viscometers are kept away from altered influences.
Especially extreme changes can be expected, for instance, during the use of liquids that attack glass, in
particular hot caustic soda hydrated (NaOH) orduring glass-blowing repairs (even for apparently
insignificant repairs).
Liquids whose components adhere to the glass wall also cause errors. In such cases, regular cleaning is
required whereby the corrosive action cleaning agent on the glass must be eliminated. For this reason,
we recommend that the user should write up a special processing instruction for all important
measurements and include them
DIN EN ISO 9001. In all cases the user is responsible for the correctness of his measuring and testing
equipment and is not released from his responsibility for quality (cp. DIN 55 350, Part 18).
6
Guarantee
We provide guarantee for the device described for two years from the date of purchase. This guarantee
covers manufacturing faults being discovered within the mentioned period of two years. Claim under
guarantee covers only the restoration of functionality, not any further claim for damages or financial loss.
Improper handling/use or illegitimate opening of the device results in loss of the guarantee rights. The
guarantee does not cover wear parts. The breach of glass parts is also excluded. To ascertain the
guarantee liability, please return the instrument and proof of purchase together with the date of purchase
freight paid or prepaid.
7
Storage and transportation
If the ViscoPump III has to be stored over some time, or to be dislocated, the use of the original packing
will be the best protection of the devices. However, in many cases this packing will not be available
anymore, so that one will have to compose an equivalent packaging system. Sealing the lower section in
a foil is hereby recommended.
The devices should be stored in a room with a temperature between +10 and +40 °C, and the (relative)
humidity of the air should not exceed 70 %.
If the interchangeable have to be stored over some time, or to be dislocated, the fluids inside the
system, especially aggressive solution have to be removed.
in his
quality management manual in accordance with
®
, however, can