Campbell CS241DM User manual

08/2021
Copyright © 2021
Campbell Scientific, Inc.

Table of contents
1. Introduction 1
2. Precautions 1
3. Initial inspection 1
4. QuickStart 2
5. Overview 4
6. Specifications 6
7. Installation 8
7.1 Wiring 8
7.2 Data logger programming 9
7.2.1 Programming 9
7.3 Placement on a photovoltaic (PV) module 10
7.4 Mounting/cable strain relief 10
7.4.1 Adhesive mounting strip 11
7.4.2 Cable strain relief 11
7.4.3 Extreme sealing tape 12
8. Operation 14
8.1 Electrical noisy environments 14
8.2 Long cable lengths 14
8.3 Modbus register map 14
8.4 Device Configuration Utility 16
9. Maintenance and troubleshooting 17
9.1 Maintenance 17
9.2 Troubleshooting 18
Appendix A. Importing Short Cut code into CRBasic Editor 19
Appendix B. Sensor material properties 20
B.1 3M F9473PC adhesive 20
Table of Contents - i

1. Introduction
The CS241DM temperature sensor uses a precision 1000 ohm Class A platinum resistance
thermometer (PRT) to measure temperature. It is designed for measuring the back-of-
photovoltaic (PV) module temperature but also can be used to measure the surface temperature
of other devices. The CS241DM has a digital RS-485 output that can be directly read by a
MeteoPV, CR6, CR1000X, or Modbus RTU RS-485 network. Other Campbell Scientific data
loggers can use an MD485 multidrop interface to read the RS-485 output.
NOTE:
This manual provides information only for CRBasic data loggers.
2. Precautions
lREAD AND UNDERSTAND the Safety section at the back of this manual.
lDo not use epoxy to secure the sensor head to a PV module.
lBefore mounting, the installers need to wash their hands and then clean the back of the PV
module or other device .
lPrying the sensor head off will likely damage both the sensor and PV module.
lProper strain relief of the cable is required after mounting the sensor to the measurement
surface (Mounting/cable strain relief (p. 10)).
lPlacement of the cable inside a rugged conduit is advisable for cable runs over 4.5 m (15 ft),
especially in locations subject to digging, mowing, traffic, power tools, animals, or lightning
strikes.
3. Initial inspection
lUpon receipt of the sensor, inspect the packaging and contents for damage. File damage
claims with the shipping company.
lThe model number and cable length are printed on a label at the connection end of the
cable. Check this information against the shipping documents to ensure the expected
product and cable length were received.
CS241DM PT-1000 Class A, Back-of-Module Temperature Sensor1

4. QuickStart
A video that describes data logger programming using Short Cut is available at:
www.campbellsci.com/videos/cr1000x-data logger-getting-started-program-part-3 . Short
Cut is an easy way to program your data logger to measure the sensor and assign data logger
wiring terminals. Short Cut is available as a download on www.campbellsci.com . It is included
in installations of LoggerNet, RTDAQ, or PC400.
The following procedure also shows using Short Cut to program the CS241DM.
1. Open Short Cut and click Create New Program.
2. Double-click the data logger model.
3. In the Available Sensors and Devices box, type CS241DM. You can also locate the sensor in
the Sensors > Temperature folder. Double click CS204DM/CS241DM. Type the RS-485
address; default address is the last two digits of the serial number. The CS241DM must have
a unique RS-485 address. The surface temperature defaults to degree C. This can be
changed by clicking the Temperature box and selecting one of the other options.
CS241DM PT-1000 Class A, Back-of-Module Temperature Sensor2

4. Click on the Wiring tab to see how the sensor is to be wired to the data logger. Click OK
after wiring the sensor.
5. Repeat steps three and four for other sensors you want to measure. Click Next.
6. In Output Setup, type the scan rate, a meaningful table name, and the Data Output Storage
Interval.
CS241DM PT-1000 Class A, Back-of-Module Temperature Sensor3

7. Select the measurement and its associated output option.
8. Click Finish and save the program. Send the program just created to the data logger if the
data logger is connected to the computer.
9. If the sensor is connected to the data logger, check the output of the sensor in the data
logger support software data display in LoggerNet, RTDAQ, or PC400 to make sure it is
making reasonable measurements.
5. Overview
The CS241DM is a surface mountable platinum resistive thermometer (PRT) that measures back-
of-module temperature for solar energy applications. It uses a precision PT-1000 Class A PRT to
provide the highest level of accuracy. To withstand the harsh treatment that commonly occurs
with meteorological station installation, the sensing element is safely housed inside a specially
designed self-adhesive aluminum disk (FIGURE 5-1 (p. 5)).
The disk protects the PRT, particularly during installation, and promotes heat transfer from the
surface. An adhesive tab on the disk fastens the sensor to the measurement surface.
The CS241DM includes a Campbell Scientific precision analog-to-digital, smart-sensor module
for making the measurements. The module design is optimized for the Class A PRT that
minimizes self-heating and wire resistance. Measurement electronics are surge protected with
1200 V isolation and environmentally protected with a rugged overmolding.
CS241DM PT-1000 Class A, Back-of-Module Temperature Sensor4

The CS241DM provides PV stakeholders with highly accurate back-of-module temperature, even
at long cable lengths, in power performance modeling and simulation of solar energy
applications. Back-of-module temperature is critical for any evaluation of effective irradiance and
power conversion.
FIGURE 5-1. CS241DM temperature sensor
Benefits and features:
lDesigned for optimal performance on bifacial PV module
lEasy installation
lNIST-traceable, serialized calibration certificate supplied with every sensor
lMeets or exceeds IEC 61724 Class A performance specifications
lPrecision PT-1000 Class A sensing element
lCompliant with IEC 60751, DIN EN 60751 (according to IEC 751)
lSlim design to minimize sensor impact on bifaciality (<2% of full-size cell area)
lThermal conductance greater than 600 W/(m2 K)
lMaximum sensor-to-module bonding
lHigh temperature rating to 150 °C
lInternal four-wire measurement with 24-bit A/D and precision resistor maximize
measurement accuracy
lCompatible with Campbell Scientific CRBasic data loggers: CR6, CR1000X, CR3000 (with
MD485), CR800 series (with MD485), CR300 series (with MD485), CR1000 (with MD485)
lEasily interfaces with the MeteoPV platform without programming
lConnects directly to a Modbus RTU RS-485 network
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6. Specifications
Sensor: Precision 1000 ohm Class A platinum sensing element
Class A sensor accuracy: ± (0.15 + 0.002t) °C
Operating temperature range: –40 to 150 °C
Temperature coefficient: TCR = 3850 ppm/K
Long-term stability: Maximum R0 drift = 0.04% after 1000 hours at 400 °C
Temperature uncertainty: ±(0.3 to 0.4 °C) for the –40 to 100 °C measurement range
when using the CR1000X data logger
Disk diameter: 2.54 cm (1.0 in)
Height: 0.419 cm (0.165 in)
Disk material: Anodized aluminum
Shipping weight: 90.7 g (0.2 lb)
Analog-to-digitalmodule (DM): 24-bit ADC
A/D measurement
uncertainty: ±0.015 °C
Supply voltage: 5 to 30 VDC
Power consumption: 15 mA
Surge protection: 1200 V isolation
Environmental protection: Rugged overmolding
IP rating: IP68 rating (self certified); 1 m submersion for 90 min
Communications:
Protocol: Modbus RTU (over RS-485)
Format: 8 data bits, 1 stop bit, even parity as default (user
configurable)
Baud rate: 19200 bps as default (user-configurable)
Modbus ID: Last two digits of serial number as default (user-
configurable)
CS241DM PT-1000 Class A, Back-of-Module Temperature Sensor6

Approvals: Conforms with the Restriction of Hazardous Substances
Directive (RoHS2)
Compliance: View compliance documents at:
www.campbellsci.com/cs241dm
 Meets or exceeds IEC 61724 Class A performance
specifications
Industrial standards: Compliant with IEC 60751, DIN EN 60751,
Industrial Design (IEC Class 4) (according to IEC 751)
IP rating: IP68 rating (self certified): 1 m (3 ft) submersion for 90
minutes
EMC compliance: Conforms with Electromagnetic Compatibility Directive
(EMC)
RoHS2: Conforms with Restriction of Hazardous Substances
Directive (RoHS2)
POE compliance: POE compliant (802.3af) to 100 meters when installed per
recommendations in TIA TSB-184
CAT5e: Cable will meet CAT5e channel requirements to 100 meter
length
Sensor cable (sensor head-to-DM board)
Cable diameter: 0.216 cm (0.085 in)
Cable length: 0.9 m (3 ft)
Jacket material: White semi-gloss perfluoroalkoxy (PFA), insulated
Jacket rating: –75 to 250 °C
Minimum bend radius: 6 mm (0.25 in) at least 6 mm (0.25 in) away
from sensor disk
Connector: Circular plastic M12 , female 5-pin connector
Standard DM cable (DM board to pigtail)
Temperature rating: –40 to 105 °C
Overall cable diameter: 7.37 mm nominal ± 0.13 mm (0.29 inch nominal ± 0.005 in)
Conductor material: 22 AWG 19/0.0058 stranded tinned copper
Cable type: 4 twisted pairs twisted together and wrapped with clear
polyester tape to form a cable core
CS241DM PT-1000 Class A, Back-of-Module Temperature Sensor7

Connector: Circular, plastic, M12 male, 5-pin, A-coded connector
Jacket material: Thermoplastic elastomer, 1.07 mm (0.042 in) nominal wall
thickness (pressure)
Insulation material: High-density polyethylene 0.254 mm (0.01 in) nominal wall
thickness
Dielectric strength: 2000 V RMS
Approvals: UL AWM 2463 (80C 600V)
NEC (UL) TYPE PLTC
NEC (UL) TYPE CMX OUTDOOR – CM
CEC C(UL) TYPE CMX OUTDOOR – CM
PENNSYLVANIA D.E.P. – MSHA
7. Installation
If you are programming your data logger with Short Cut, skip and Data logger programming (p.
9). Short Cut does this work for you. See QuickStart (p. 2) for a Short Cut tutorial. This section
discusses the following:
7.1 Wiring 8
7.2 Data logger programming 9
7.3 Placement on a photovoltaic (PV) module 10
7.4 Mounting/cable strain relief 10
7.1 Wiring
The DM module is embedded in a short cable that attaches to the sensor head and has a 5-pin,
M12 female circular connector. A standard cable or a 3-twisted-pair shielded cable with a 5-pin
M12 male circular connector is used to attach the sensor to the station or data logger (Table 7-1
(p. 9)). Using connectors between the sensor head and the station or data logger cable allows in-
field sensor head replacement without disconnecting the cable from the data logger.
The following table provides sensor wiring and cable pin-out. Detailed information about the
cables are provided in the Specifications (p. 6). Sensor wiring is also available in the Device
Configuration Utility and the MeteoPV User Interface.
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