Measuring With Ntc Probes; Measuring With Ptc Probes - Omega DP20 User Manual

DP20 Economical Multisignal Meter

1.14 Measuring with NTC probes

• Accepted NTC probes
The NTC probe is a temperature variable resistor
with a temperature - resistance curve defined by two
parameters called 'R25' and 'beta'. By default, the
instrument is configured for a standard NTC with 'R25'
of 10K and 'beta' of 3500. The measured temperature ranges from
-60 ºC to 150ºC.
Different NTC probes can be used, by configuring the instrument for
different values of 'R25' and 'beta'. The instrument measures
resistance from 100 R up to 1 MOhm. Use 'Table 12' to write down
values for your NTC.
• Parameters 'R ' and 'Beta'
25
The instrument accepts values of 'beta' between 2500 and 5500,
and values of R25 between 1.0 K and 200.0 K
• Resolution and units
The temperature resolution using NTC temperature probes is
configurable to 1º or 0.1º. Reading can be configured in ºC (degrees
Celsius) or ºF (degrees Fahrenheit).
NTC Jumper 'S'
'R '
25
(configurable)* (see section 1.9)
10K F K
Table 13 - *'Beta' is configurable from 2000 to 5500. 'R25' is configurable from 1.0 K up to 200.0 K.

1.15 Measuring with PTC probes

• Accepted PTC probes
The instrument accepts direct connection of PTC
probes. Accepted PTC probes are listed at 'Table 14'.
• Resolution and units
The temperature resolution using PTC temperature probes is
configurable to 1º or 0.1º. Reading can be configured in ºC (degrees
Celsius) or ºF (degrees Fahrenheit).
Family Sensor
(see section 1.9)
KTY81-121
KTY 121
KTY82-121
KTY81-210
KTY 210
KTY82-210
KTY81-220
KTY 220
KTY82-220
Table 14 - Ranges of temperature for PTC probes
Jumper 'T' Range
(see section 1.9) of measure
from -60ºC
4-5
to 150ºC
Jumper 'S' Jumper 'T'
(see section 1.9)
F
FHK 4-5
FHK
• Sensor break detection
In case of sensor break, the instrument will show 'h.ovr' or 'h.udr'
(see Table 18) depending on the broken cable.
• Terminal 5 'multifunction' - External control
Terminal 5 remains configured as 'EK' external control function. See
section 1.9 for a list of available functions.
• Start-up, connections and jumpers
For instrument start-up follow the steps listed at section 1.7. Signal
connections are indicated at section 1.5. Location for internal
jumpers is indicated at section 1.9.
See below connections for NTC probe :
Accuracy Connection
(% of reading)
(
terminals)
<1.5% of 2 (NTC +)
reading 4 (NTC -)
• Sensor break detection
In case of sensor break, the instrument will show 'h.ovr' or 'h.udr'
(see Table 18) depending on the broken cable.
• Terminal 5 'multifunction' - External control
Terminal 5 remains configured as 'EK' external control function. See
section 1.9 for a list of available functions.
Range in ºC Total error
(in ºF)
-55 / 150 ºC
<1º
(-67 / 302 ºF)
12
1 2 3 4 5
ntc -
ntc +
Beta Range
(configurable)
of measure
100 R
3500
1 MOhm
Table 12 - Data from NTC datasheet
• Start-up, connections and jumpers
For instrument start-up follow the steps listed at section
1.7. Signal connections are indicated at section 1.5.
Location for internal jumpers is indicated at section 1.9.
See below connections for PTC probe :
1 2 3 4 5
ptc -
ptc +
Instruction Manual
NTC probe
Temp. R25 Beta