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The
fl
ow in your instrument is outside tolerance range
This warning appears if the
fl
ow as measured by the internal sensor falls under 0.95 liters/minute. In this
case, you should check the
fl
ow rate by pressing the
fl
ow button in the toolbar. A too low
fl
ow can be caused
by different things: (1) pump failure, easily detected by the absence of any vacuum at the inlet of the testo
DiSCmini, and a
fl
ow of about 0.3lpm displayed
(2) external clogging of a tube when using the tube inlet, or (3) clogging of the impactor ori
fi
ces – in both
cases (2) or (3) check whether the
fl
ow is normal when you have the Testo DiSCmini running with only the
tube inlet
fi
tting. If you notice that the testo DiSCmini does not reach the nominal
fl
ow with the impactor inlet,
you should clean the impactor. (4) internal clogging of the
fi
lter in the
fi
lter stage – this should only happen if
you also have a warning that your instrument needs servicing.
Troubleshooting
Problem
Solution
dirt on counter electrode
or
High voltage in charger
not present, although it is
turned on.
If the charger is exposed to too much coarse dirt, small conductive dirt par-
ticles can produce a short circuit between the electrode and the charger
housing. In this case, testo DiSCmini will measure a large diffusion current
through the short circuit, and regulate the Corona voltage to 0V.
The
fi
rmware detects this error and report „dirt on counter electrode“
The charger is not user-serviceable. Please contact Testo or your local distri-
butor for service.
Noise levels too high
Run testo DiSCmini with
fi
ltered and dried air for several hours to remove a
water
fi
lm on the insulators, which can form at high RH conditions.
If the problem persists, contact Testo or your local distributor for support.
Zero offsets too far away
from 0
Large / unstable zero offsets is a sign for contaminated insulators. Run testo
DiSCmini for several hours with
fi
ltered and dried air and see whether this sol-
ves the problem. If the problem persists, contact Testo or your local distributor
for support.
Known Issues
This section lists all known issues with testo DiSCmini.
• Due to the measurement principle of testo DiSCmini, the instrument can produce wrong results if the
incoming aerosol is highly positively charged: if particles carry a higher positive charge than that which
they would get in the testo DiSCmini charger, the current in the electrometer stages will be higher than
expected, and testo DiSCmini will report a higher concentration than what is really there.
• The instrument is calibrated for a size distribution with a given shape (lognormal with a geometric stan-
dard deviation of 1.9).
Service and Maintenance
The service and calibration of your testo DiSCmini have to be done once a year. If you use it for continuous
long-time measurements, we recommend to maintain and calibrate it more often.
For service and maintenance and for calibration you have to send the testo DiSCmini to the manufacturer
Testo SE & Co. KGaA or to your local distributor.
Electric shock
Hazardous voltage inside. Contact may cause electric shock or burn. Do not open
coverage of testo DiSCmini.
