TESTO 312-4, Инструкция по эксплуатации

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6 Using the product
29
5. Calculate the multi-point mean with .
- The calculated mean is displayed and can be stored or printed
out.
> Reactivate the mean calculation with .
> Cancel the process with .
6.3. Perform measurement procedures
Special measurement procedures are saved in the instrument that
support you when performing special measuring tasks.
6.3.1. Pretest/main test, high pressure at water pipes
Pretest and main test at gas pipes in acc. with
DVGW-TRGI 2008 worksheet G 600
The pretest (using air) is used for the load test (stability test) of
newly laid gas pipes. The test is performed at the pipe without gas
meter and fittings. The pipe is pressurized with 1 bar and the
pressure may not drop within 10 minutes. The measurement is
performed using a high-pressure probe (25 bar).
The main test (using air or inert gas, e.g. CO
2
or N
2
) is used for the
leak test (acceptance inspection) of newly laid or restructured
pipes. The test is performed at the pipe, including the fittings,
without gas installations and corresponding control and safety
equipment. The line must be pressurized with 110 mbar which must
remain constant for 10 minutes for this test.
High pressure at water pipes
The high pressure measurement at water pipes is performed in
accordance with the same measurement procedure as a pretest at
gas pipes. Use the
Pretest measurement procedure for this.
Connecting the instrument
> Connect the instrument as suits the measurement task
(pretest/high pressure or main test), see Connection variations,
page 24.