Delta OHM DO2003, Manual

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T
EMPERATURE
M
EASUREMENT
Pt100 (100 Ω @0°C) temperature probes can be connected to both A and B inputs; all probes are
factory calibrated. You can choose between °C and °F every time you have to display or print any
value.
To carry out a temperature measurement by
immersion, put the probe (for 60 mm, at least) into the
liquid where you want to make the measurement; the sensor is placed inside the tip of the probe.
For
penetration
measurements, the tip of the probe has to penetrate for 60mm at least, the sensor is
placed inside the probe tip. In order to measure temperature in frozen blocks, it is convenient to use
a mechanical tool to make a hole where a pointed probe has to be introduced.
To make a correct
surface (contact) measurement, the surface to be measured has to be flat and
smooth, the probe has to be perpendicular to the plane to be measured.
Interposing a drop of conductive paste or oil (do not use neither water nor solvents) would
help make a correct measurement. Furthermore, this improves the response time, too.
R
ELATIVE
H
UMIDITY
M
EASUREMENT
The Relative Humidity probe has to be connected to input B of the instrument. Humidity probes
provided for a DO2003 are RH/ temperature ones: the humidity sensor is capacitive type, while the
temperature one is a Pt100. The probes are provided with an 8-pole DIN connector module having a
microprocessor circuit with a permanent (non-volatile) memory to store calibration data.
The instrument measures both relative humidity and temperature and, starting from a 1013.25mbar
barometric pressure fixed value, it calculates the following derivative quantities:
1.
g/m
3
= grams of vapour in a cubic metre of dry air
2. Td = dew point (in °C or °F)
3. DI = Discomfort Index
4. ET = Net Index
Use the UNIT B key to select the quantity to be viewed on the display second line.
For more details concerning the meaning of Discomfort index and Net index, see the paragraph
Humidity and Quality Indices (Comfort indices) at page 29.
The measurement by means of a RH/temperature probe has to be carried out introducing the probe
in the area where you want to record the parameters. Keep the probe far from elements that might
interfere with measurements, such as heat or cool sources, walls, air-streams, etc. Avoid sudden
rises/falls in temperature that would cause condensate. Reading in a condition with no thermal
shocks is practically immediate; on the contrary, in a condition involving thermal shocks, you have
to wait until the probes and their housing have reached a thermal equilibrium to prevent irradiation
or heat absorption on the relative humidity sensor, which would cause a wrong measurement:
temperature affects relative humidity.
C
ALIBRATION OF A
RH/T
EMPERATURE
P
ROBE
The instrument is already calibrated and, normally, no additional calibration by the user is required.