Novus RHT-WM User manual

NOVUS AUTOMATION 1/6
RHT-WM and RHT-DM Transmitter
INSTRUCTIONS MANUAL - V1.2x G
CE Mark
This is a Class A product. In a domestic environment, this product may cause radio interference in which case the user may be required to take
adequate measures.

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1PRESENTATION
The RHT-WM and RHT-DM transmitter series incorporate the best high accuracy and great stability relative humidity and temperature sensors.
They convert the measured values into linear 4 to 20 mA signals and optional 0 to 10 Vdc output can also be offered under request.
The microprocessor based circuit enables full configuration of output range when used with the TxConfig PC interface and the Windows®
software. The humidity signal can be configured to either Relative Humidity or Dew Point output.
2INSTALLATION
2.1 MECHANIC INSTALATION
The RHT-DM (Duct Mount) model transmitter should be installed with a flange. This flange is first screwed onto the duct wall and the transmitter
probe is then inserted into the flange central hole and locked. Fig. 1 shows the dimensions and holes of this flange, which can be made of stainless
steel or polyamide 6.6
Fig. 1- Mounting flange for RHT-DM
The probe is made in stainless steel, with standard lengths of 150 mm, 250 mm and 400 mm.
Fig. 2- Model RHT-DM dimensions
The model RHT-WM (Wall Mount) was designed to be mounted directly onto a wall. With the cover off, the user can access the 2 fixing points and
the signal connector, as shown in Fig. 3. The transmitter sensor capsule must be placed faced down in order to assure the specified
accuracy and protection level.
Fig. 3 - RHT-WM fixing holes and housing dimensions

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2.2 ELECTRICAL INSTALLATION
The transmitter can be ordered as 4-20 mA current output or 0to 10 Vdc voltage output. The output signal type is defined at the time of purchase
of the transmitter and cannot be changed later.
Variables can be monitored together or separately. Combinations of mobile jumpers J4 and J5 within the transmitter case define how variables will
be used. The jumpers also define the transmitter terminals with available output signals.
Jumper J5
Jumper J4
OUT1
OUT2
Position A
Position A
Temperature
Humidity
Position A
Position B
Temperature
Off
Position BPosition AHumidity Off
Position BPosition BHumidity Temperature
Table 1 - Configuration of OUT1 and OUT2 outputs
Fig. 4- Location of J4 and J5 jumpers inside the transmitter
Fig. 5and Fig. 6show the required electrical connections.
Note that loop OUT1 must always be powered in the 4-20 mA model!
Fig. 5a - 4-20 mA connections Fig. 6a - 0-10 Vdc connections
Fig. 5b - 4-20 mA connections with single source Fig. 6b - 4-20 mA model with single source and load with two input
channels
In the figures above, LOAD represents the measuring instrument of the output signal (indicator, controller, register, etc.).
The connection wires go inside the transmitter trough to the cable gland mounted in the transmitter case.
INSTALLATION RECOMMENDATIONS
•Conductors of small electrical signals must be distant from activation or high-tension/current conductors, preferably passing through grounded
conduits.
•A specific electrical power supply network should be provided for instruments use only.
•In controlling and monitoring applications, possible consequences of any system failure must be considered in advance.
•RC filters (47 R and 100 nF, serial) in inductor charges (contactors, solenoids, etc.) are recommended.

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CARE WITH THE SENSORS
The calibration of the humidity sensor may change in case it is exposed to contaminating vapors or to high humidity and temperature conditions for
extended periods. In order to speed up the calibration restoration, proceed as described below:
•Remove the sensor from the capsule.
•Wash it with water in case there are solid particles on it.
•Place it within an 80 °C (±10 °C) oven for 24 hours.
•Place it for 48 hours in a place with a temperature between 20 and 30 °C and humidity over 75 % RH.
•Place the sensor back in the capsule.
3CONFIGURATION
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 USB
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. 7.
Fig. 7 – TxConfig Interface USB connections
Once the connection is accomplished, the user must run the TxConfig software and, if necessary, use the Help topic to arrange the transmitter
configuration.
A Fig. 8 shows the TxConfig software main screen.
Fig. 8 – TxConfig software main window
The fields in the screen mean:
1. Measuring Range: Define the transmitter humidity and temperature measurement ranges, indicating a Lower Limit value and an Upper Limit
value.
The defined range cannot exceed the Sensor Measuring shown in this same field, and also cannot establish a range with a span less than the
Minimum Range indicated below in this same field.
When the Lower Limit is set to a value higher than the Upper Limit, the output current has a decreasing behavior (20 ~ 4 mA or 10 ~ 0 V).

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2. Sensor Failure: Establish the transmitter output behavior in the presence of a sensor fail. When Minimum is selected, the output assumes its
minimum value (4 mA / 0 V) (down-scale). When Maximum is selected, it assumes its maximum value (20 mA / 10 V) (up-scale).
3. Zero Correction: Correct, in the output value, small measurement errors presented by the transmitter.
4. Device Information: This field contains data that identifies the transmitter and is important in any queries to the manufacturer.
5. Read Device: When selected, allows you to read the configuration present on the connected transmitter.
6. Apply: When pressed, allows you to send the configuration to the connected transmitter.
Note: The factory default configuration is (unless otherwise specified or ordered):
•Measuring ranges: 0 to 100 °C and 0 to 100 % RH;
•0 °C of correction zero;
•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:
The humidity sensor has a maximum range of 0 to 100% RH and an accuracy of 3% at 25 ° C, as shown in Fig. 10. We can have an error of
up to 3% RH in any adopted range.
This error is even in a wide range as the maximum (0 to 100% RH) or in a narrower range, such as 20 to 80% RH.
Serial port configuration error may occur when other software uses the same serial port. Finalize all software that uses the serial port
specified for TxConfig before using it.
RETRANSMITTING THE DEW POINT
To use the RHT and transmit the dew point instead of relative humidity, you must follow the following steps:
•Connect the device to the TxConfig interface and run the software.
•The software will recognize the RHT model, read its configuration and make it available to the user.
•In the "Options" menu, enter "Humidity Reading Type" (only available when an RHT model is detected) and select the "Dew Point" option. At
this point, the values of the scales will be converted to the dew point unit, ie degrees (Celsius or Fahrenheit, as selected).
•Proceed with the rest of the configuration and send the device via the "Apply" button.
Fig. 9 – Dew point
If the "Humidity Reading Type" option does not appear even after the RHT transmitter is correctly detected, the TxConfig software version is
probably old and does not support this feature. In this case, download and update the latest version.

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4SPECIFICATIONS
Humidity measurement
Total accuracy: See Fig. 10;
Measuring range: Configurable between 0 and 100 % RH or -100 and 103 °C for dew point;
Response time (1/e (63 %)): 8 seconds @ 25 °C (is slow moving air 1 m/s).
Temperature measurement
Total accuracy: See Fig. 10;
Total accuracy: Configurable between -40 and 120 °C;
Response time (1/e (63 %)): up to 30 s (is slow moving air 1 m/s).
Power supply 4-20 mA model: 12 Vdc to 30 Vdc
0-10 V model: 18 a 30 Vdc / 15 mA max.
Outputs 4-20 mA or 20-4 mA current, 2-wire loop power supply;
0-10 Vdc tension / 2 mA max.
Output Load (RL) 4-20 mA model: RL (Ohms max.) = (Vdc - 12) / 0.02 let: Vdc= Power supply in Volts.
0-10 Vdc model: 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).
Isolation between loops The 4-20 mA outputs are isolated from each other.
The 0-10 V is not isolated from each other.
Provides protection against
power supply polarity
inversion
Yes
Protection Electronic circuit case:IP65;
Sensors capsule: IP40.
Cable entrance Compress fitting PG7.
Operating limits Sensor and Probe (RHT-DM): See Fig. 10.
Electronic circuit Electronic circuit (WM/DM): -10 to +65 °C, 0 to 95 % RH.
Table 2 – Technical specifications
IMPORTANT
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. 10 - Humidity and temperature accuracies
5WARRANTY
Warranty conditions are available on our web site www.novusautomation.com/warranty.