5
2. When installing the remote
probe in pipelines or vessels,
disconnect the probe from the
transmitter to prevent breaking
wires in the probe assembly.
Reconnect the probe to the
transmitter after the probe is
installed. *
The probes are
not interchangeable as
each probe has its cali-
bration data stored in an
EEPROM on the trans-
mitter
.
3. Connect the transmitter to a 18
to 28 volt DC power supply and
turn power on.
4.
Wait for the dew point reading
to stabilize. The transmitter
range is limited by the response
of the internal sensor.
There is
no over/under range indica-
tion, and the accuracy is not
rated beyond -40°F to +80°F
(-40°C to +20°C).
RECALIBRATION
The DPX-200 is a microprocessor
based-instrument and has no user
adjustments. *
The probes are
not interchangeable as
each probe has its calibra-
tion data stored in an
EEPROM on the transmitter
.
The system can be recertified to
NIST traceable standards by return-
ing it to Ohmic Instruments Co.
Recertification is recommended on
a yearly basis.
OPTIONAL RS-232 INTERFACE–
Connecting the DPX-200 to Your
Computer
Connecting to a serial port If your
DPX-200 includes the optional RS-
232 adapter cable, it can be con-
nected to your computer’s 9-pin PC
serial (COM) port. If your computer
has a 25-pin COM port, 25-pin to 9-
pin serial adapters are available from
most computer stores and can be
used with the adapter cable [Serial
data is transmitted using Pin 5
(ground), Pin 3 (transmit), and Pin 2
(receive)]. Some computer COM
ports and serial adapters are not fully
implemented (not all pins are used).
If the DPX-200 is connected to a
partially implemented serial port,
functions may be erratic or the unit
may fail to communicate. Consult the
owner’s manual for your computer if
this occurs. Set up your communica-
tions program as described on Page
6.
Connecting to a USB port If your
DPX-200 includes the optional RS-
232 adapter cable, it can be con-
nected to your computer’s USB port
via an optional RS-232 to USB
adapter from Ohmic. Ohmic recom-
mends using an RS-232 to USB
adapter only with Windows XP
©
and
later versions. Connect the DPX-200
using the RS-232 adapter and RS-
232 to USB adapter. Turn on your
computer. When your computer rec-
ognizes the device click OK and fol-
low the instructions for installing the
driver software. Set up your commu-
nications program as described on
Page 6.
