Temperature Measurements; Decibel Measurements - Hameg Instruments HM8010 Manual

Temperature measurements

Choose the temperature measurement function
18 ,
(°C or °F) using
ture probe is connected between the COM ter-
minal and the V/Ω/T°/dB terminal
Temperature measurement requires a tempera-
ture probe type PT100 as per standard EN60751.
The use of another probe is possible but can
generate additional errors due to a different link
cable resistance. All keys except
HOLD/OFFSET are inactive for this function.
After the instrument has been turned-on, the line
resistance value of the temperature probe is
automatically compensated.
On starting, simultaneously pressing BEEP
and OFFSET will eliminate probe cable
resistance compensation (zero value). In all
cases, compensation can be carried out by setting
the probe to a temperature of 0 °C and using the
OFFSET function.
Note: Measurement of the temperature probe
line resistance should be made on the same
instrument used for temperature measurements.
Only this procedure guarantees the specified
measurement error.

Decibel measurements

Choose the decibel measurement function using
18 , 17 key. For decibel measurements, the
unknown input voltage is connected between the
COM terminal and the V/Ω/T°/dB terminal.
The HM8010 is used for DC or AC voltage mea-
surements in decibels. The 0 dB reference is
defined for 1 mW power in a 600 Ω load., i.e. a
voltage of 0.7746 V. The scale extends from –
78 dBm to 59.8 dBm.
In a 50 Ω-system, the reference voltage for 1mW
power is 0.2236 V. In a 75 Ω-system, the
reference voltage for 1 mW power is 0.2739 V.
If decibel measurements are made on a 50 Ω-
system, add 10.8 dB to the displayed value. If
decibel measurements are made on a 75 Ω-
system, add 9 dB to the displayed value. The
mathematical relationship is as follows:
17 key. The tempera-
.
18 , 17 and
R= Reference resistance in Ω ; P
Sign consideration: A displayed value of –12 dB
is equivalent in 50 Ω to: –12 dB +10.8 dB = –1.2 dB
Subject to change without notice
F u n c t i o n s
= 1 mW; V in V
0 0
29