Sensores de punto de rocío DMT242

Sensores de punto de rocío DMT242
P.O. Box 26, FI-00421 Helsinki, Finland
Tel. +358 9 894 91
Fax: +358 9 8949 2485
Email: [email protected]
www.vaisala.com/DMT242
DMT242 Dewpoint Transmitter for
OEM Applications
Features/Benefits
Due to its wide measurement
range and high long-term
stability, the DMT242 is an
ideal choice for low dewpoint
industrial applications such
as compressed air dryers,
plastic dryers and other OEM
applications.
The Vaisala DRYCAP® Dewpoint
Transmitter DMT242 provides reliable
and stable measurements for low
dewpoint industrial dryer applications.
It provides a fast response time and
wide measurement range: measuring
from -60 to +60 °C (-76 ... +140°F) with
an accuracy ±2 °C (±3.6 °F) over the
entire specified process temperature
range.
Vaisala DRYCAP®
performance
The DMT242 incorporates the Vaisala
DRYCAP® thin film polymer sensor
and auto-calibration software, a
combination that makes it ideal for use
in dry conditions.
The sensor is immune to particulate
contamination, water condensation,
oil vapor, and most chemicals. As the
sensor withstands condensation, its
performance is unmatched for low
dewpoint applications that experience
process water spikes, such as pipeline
condensation during a system failure or
start-up.
The auto-calibration software works
on-line while the process is running.
If the measurement accuracy is
not confirmed, the software makes
the corrections to the calibration
curve. Corrections may be due to
contamination or aging of the sensor. In
either case the transmitter adjusts the
measurement, corrects dry-end drifts
and continues to function. Calibration
occurs quickly with corrections so
minor that the user will not realize it
has taken place.
The user can perform field-check by
using Vaisala DRYCAP® Hand-Held
Dewpoint Meter DM70. The transmitter
can be sent to Vaisala Service for NIST
traceable calibration. Calibration
intervals depend on the application; the
recommended calibration interval is
every two years.
Compact, rugged and
intelligent
The DMT242 is designed for extreme
conditions that require protection
against dust, dirt and splashed water.
• Ideal choice for low dewpoint
industrial dryer applications
• Incorporates advanced Vaisala DRYCAP® Sensor and enhanced auto-calibration software
• Long-term stability in low dewpoints
• Fast response time
• Wide dewpoint measurement range
from -60 … +60 °C (-76 … +140 °F)
with an accuracy ±2 °C (±3.6 °F)
• Withstands condensation
• IP65(NEMA 4) housing provides protection against dust, dirt and
splashed water
• Can be installed directly into systems
at 20 bar maximum pressure
• NIST traceable (certificate included)
• Compatible with Vaisala DRYCAP® Hand-Held Dewpoint Meter DM70
The housing offers IP65- protection and
the transmitter can be installed directly
into systems at 20 bar maximum
pressure.
Due to its compact size, DMT242 is
quickly and easily installed in tight
spaces. Units are delivered installation­
ready. If necessary, re-scaling the output
can be done via the serial interface.
The supply voltage and output signal
connect easily to the IP65 (NEMA 4)
protected screw terminals. A separate
serial output is available for service use
The Vaisala
DRYCAP® HandHeld Dewpoint
Meter DM70
is ideal for
confirming the
performance of
the DMT242 in
the field.
DMT242
DEWPOINT
Technical Data
Dewpoint temperature
Dewpoint temperature (˚C)
Measurement range (typicalI
-60 ... +60 °C (-76 ... +140 °F)
Analog output scalings
Option A
-80 ... +20 °C (-112 ... +68 °F)
Option B
-60 ... +60 °C (-76 ... +140 °F)
Option X
free scaling
(when the dewpoint is below 0 °C (32 °F), the transmitter outputs
frostpoint)
±2 °C (±3.6 °F)
Accuracy with DRYCAP® 180M
(see graph below)
70
60
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
y < ± 2˚C
Accurac
Td
er limit
ment range low
sure
Dewpoint mea
0
10
40
30
20
60
50
Process temperature (˚C)
General
Sensor
Optimal sensor for refrigerator dryers
Operating voltage
DRYCAP® 180M
DRYCAP® 180S
17 - 35 VDC
20 - 28 VDC
max. 220 mA
max. 500 Ω
Power consumption at 24 VDC
External load for analog output
Optional connection cable with
DMT242 connector
2 m or 10 m
Connector for supply voltage and signal output
max. wire size
0.75 mm2
max. cable diameter
6.5 mm /PG7
Service cable for serial interface
RS232
product code DMT242RS
Probe material (wetted parts)
stainless steel
(AISI 316L)
Sensor protection
stainless steel
sintered filter (HM47280)
Mechanical connection
G½” ISO228-1 thread
with bonded seal ring
(U-seal)
Eletronics housing material
plastic (ABS/PC)
Housing classification
IP65 (NEMA4)
Storage temperature range
-40 ... +70 °C
(-40 ... +158 °F)
Dewpoint accuracy vs. measurement conditions
Response time 63 % [90 %] at +20 °C gas temperature
Flow rate >1 l/min and 1 bar pressure
-60 -> -20 °C Td (-76 -> -4 °F Td)
5 s [10 s]
-20 -> -60 °C Td (-4 -> -76 °F Td)
45 s [10 min]
Complies with the EMC standard EN61326-1, Electrical
equipment for measurement, control and laboratory use EMC requirements; Industrial environment.
Accuracy with DRYCAP 180S
Dimensions in mm
±2 °C (±3.6 °F)
(see graph below)
Dewpoint temperature (°C)
®
70
60
50
40
30
20
10
0
-10
-20
-30
-40
-50
-60
-70
-80
vap
Water
ra
or satu
Dimensions
e
tion lin
y < ± 2°C
Accurac
Td
it
lower lim
urement range
Dewpoint meas
0
10
20
30
40
50
60
Process temperature (°C)
Temperature
higher temperature peaks
Relative humidity
Pressure
Sample flow rate
Output
Analog output
Resolution for analog output
Typical temperature dependence
Serial line for service use
0 ... +60 °C (32 ... +140 °F)
Short-term OK
0 ... 100 %RH
0 ... 20 bara (0 ... 290 psia)
no effect
4 ...20 mA
±0.002 mA
0.0008 mA/ °C
RS232
Wiring
Wiring of the connector
1
2
3
1
= V supply+ (VAC line) (Brown)
= V supply- (VAC neutral)/signal - (Blue)
= signal + (Black)
= no connection
DRYCAP® is a registered trademark of Vaisala.
Specifications are subject to change without prior notice.
©Vaisala Oyj
Ref. B210765EN-A 2008-07
Operating environment
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