NOVUS RHT - D M - Manual (Page 2)

SPECIFICATIONS
Humidity measurement:
Accuracy: Refer to Fig. 01;
Repeatability: ± 1 % RH;
Non-linearity: << 1 % RH;
Stability: < 1 % RH / year;
Span: any value between 0 and 100 % RH or -100 and 103 ºC for dew point;
Response time: 4 seconds in slow moving air (63 %);
Temperature channel:
Accuracy: Refer to Fig. 01;
Repeatability: ± 0.1 ºC;
Response time: up to 30 seconds in slow moving air (63 %);
General specifications:
Power supply: 12 Vdc to 30 Vdc (4-20 mA model)
18 to 30 Vdc / 15 mA. (0-10 V model)
Outputs: 4-20 mA or 20-4 mA current, 2-wire loop power supply;
0-10 Vdc / 2 mA max. (0-10 V model)
Output Load (RL): 4-20 mA output: RL (Ohms max.) = (Vdc – 12) / 0.02
let Vdc = Loop power supply (12 to 30 Vdc).
0-10 Vdc output: 2 mA max.
OUT1 output resolution: 0.006 mA (4-20 mA) or 0.003 V (0-10 V);
OUT2 output resolution: 0.022 mA (4-20 mA) or 0.015 V (0-10 V);
Channel isolation: the 4-20 mA outputs are isolated from each other. The 0-10 V outputs
share a common ground;
Reverse polarity protection: YES
Protection: Electronic circuit case: IP65; Sensors capsule: IP40
Cable entrance: Compress fitting PG7;
Operating limits: Sensor and probe (RHT/DM): see Fig. 01;
Electronic circuit: -10 to +65 °C, 0 to 95 % RH.
IMPORTANT NOTE:
The transmitter sensor may be damaged or lose calibration if it is exposed to aggressive
atmospheres with high concentrations as Chloride Acid, Nitride Acid, Sulphuric Acid and
Ammonia. Acetone, Ethanol and Propylene Glycol may cause reversible measurement errors.
Measures accuracy and sensor operating limits:
Fig. 01 - RH and Temperature accuracies
CONFIGURATION
If the default configuration or the ordered configuration satisfies the application, then no further
configuration is necessary and the transmitter is ready to be used. If a new setting is desired,
this can be accomplished by the TxConfig and sent to the transmitter through the TxConfig
interface.
The TxConfig Interface and Software compose the Transmitter Configuration Kit, with can be
purchased separately from the manufacturer or one of its distributors. The latest release of this
software can be downloaded from our web site. To install, run the Tx_setup.exe and follow the
instructions.
The TxConfig interface connects the transmitter to the PC, as shown in Fig. 02 and 03. There
are two types of interface: TxConfig-RS232 and TxConfig-USB.
Fig. 02 – TxConfig Interface connections model RS232
Fig. 03 – TxConfig Interface USB connections
Once the connection is accomplished, the software shows the configuration options of the
transmitter model attached. Access the Help for usage instructions.
Fig. 04 shows the TxConfig sotware main screen.
Fig. 04 – TxConfig software main window
The fields in the screen mean:
1. Measuring Range: Defines the output scale for the input sensor. Program here the
measurement Lower Range Value and the Upper Range Value.
The values configured in these fields can not be beyond the sensor measuring range. The
minimal span value has to be observed as well.
When the lower limit is defined with a value higher than the Higher Limit the output current
operates from 20 to 4 mA.
2. Sensor Failure: establishes the transmitter output behavior (upscale or down-scale) in the
presence of a sensor fail. When Minimum is selected, the output current is < 4 mA (down-
scale), typically used for refrigeration. When Maximum is selected, the output current is > mA
(up-scale), typically used in heating systems.
3. Zero Correction: Allows for small sensor corretions.
4. Device Information: Transmitter identification data. These information must be informed
when the user contact us.
5. Read Device: Brings to the screen the current transmitter parameters configuration.
6. Apply: Sends a new configuration to the transmitter.
Note: The factory default configuration is (unless othenrwise specified or ordered):
• RHT sensor, temperature span 0 to 100 ºC and humidity span 0 to 100 % RH;
• 0 °C of zero correction;
• Upscale when sensor fails.
It is important to notice that the transmitter accuracy is always based on the total span of the
used sensor, even if a narrower range is configured. Example:
Humidity sensor has a total span of 0 to 100 % and accuracy of 3 % at 25 °C, as showed in
Fig. 01. This 3 % RH error is the same no matter if the total span is configured (0 to 100 %)
or a narrower span (like 20 to 80 %).
During configuration, the transmitter needs to be electrically powered. TxConfig-USB interface
can provide the power to the transmitter, but this also depends on the used computer hardware.
The TxConfig-RS232 interface, however, requires an auxiliary supply for guarantee reliable
communication with the computer. An external 9 V battery can be used for this purpose (Fig. 02).
An alternative is to configure the transmitter while it is in operation; this way, the needed energy is
supplied by the current loop. See Fig. 05.
Fig. 05 – TxConfig Interface connections – Loop powered
The TxConfig interfaces contain dedicated circuitry for proper
communication between transmitters and computer. Always make use of
the TxConfig interfaces for configuration purposes, otherwise the
transmitters may get damaged, voiding the warranty.
Serial port configuration errors may occur when other software are sharing the same
serial port. Close all serial port applications prior to using the TxConfig software.