Delta-T Devices SPN1-MS1 User manual

SPN1-MS1 – Instructions v1.6 6/11/06
Delta-T Devices Instruction Sheet
Sunshine Pyranometer type SPN1-MS1
SPN1-MS1 Instructions
Introduction
The SPN1-MS1 is a special development for MeteoSwiss
of the standard SPN1 Sunshine Pyranometer with the
following features:
•Fits the MeteoSwiss heating and ventilating dome.
•Lemo connectors are provided for the data logger and
serial connections.
•Custom firmware provides a sunshine duration
threshold of 200 W.m-2 in the direct beam.
Check Packing List
The SPN1-MS1 is supplied with a 5-pin and an 8-pin Lemo connector, and a calibration certificate.
Mounting and Connections
Use the three M5 tapped holes in the base to mount the SPN1 inside the MeteoSwiss heating and
ventilating dome. Do not touch any socket cap screws under the flange holding the dome. These are
sealed during manufacture. Mount the dome horizontally – no polar alignment or routine adjustment
needed. Connect the power, data logger, and serial port if required, using the connection details below.
Data Logger
Connection
using 8-pole Lemo plug
Pin Function Notes
1 Total Total output: 1mV = 1W.m-2
2 Diffuse Diffuse output: 1mV = 1W.m-2
3 Sig Gnd Signal ground
(connected internally to Power 0V)
4 Sun Contact closure on Sunshine
5 Power 0V
6 Power V+
Power for SPN1-MS1 electronics,
5 - 15V DC, 2mA **
7 Htr -
8 Htr +
Power for internal SPN1-MS1
heater, 12V DC, 1.5A max **
Shell Screen Connects to SPN1-MS1 case *
Pin 1 (Total output) and pin 2 (Diffuse output):
connect to data logger voltage inputs.
The normal range of this output is 0V – 1.5V
Pin 3: connect to data logger signal ground or –ve
input terminal.
Pin 4: connect to a data logger digital input. It gives a
short circuit to ground when sunshine is present, and
open circuit with no sunshine. Alternatively, connect
to a resistance input, with a precision resistor in
parallel.
Pins 5 and 6 (SPN1-MS1 power): apply >5V to power
the SPN1 and enable the sensor output signals.
Pins 7 and 8 (internal heater power): connect to a
12V DC 1.5A power supply. The actual heater current
depends on the temperature. This internal heater may
not be needed if using the MeteoSwiss heating and
ventilating dome
Serial Port
Connection
using 5-pole Lemo plug
Pin Function Notes
1 GND Ground
2 CTS Power for SPN1-MS1 electronics.
Connect to RTS of PC serial port **
3 Rx Received data into SPN1-MS1
4 - (not implemented)
5 Tx Transmitted data from SPN1-MS1
Shell Screen Connects to SPN1-MS1 case *
* Note: Use screened cable. Clamp braid to connector
shells and terminate at datalogger or PC case or ground. To
avoid ground loops do not interconnect braids elsewhere.
** Note: the SPN1-MS1 draws power from Power V+, CTS,
or Htr +, whichever provides the highest voltage.
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Maintenance
Keep the glass dome clean using clean water, with mild detergent or Isopropyl Alcohol for difficult deposits.
If any two of the three blue desiccant indicators turn pink - unscrew the desiccant capsule from the indicator cap,
and replace with a fresh one (type SPN1-SD). Recalibration every 2 years is recommended.
SPN1-MS1 Specifications
The following accuracy figures give 95% confidence limits, i.e. 95% of individual readings will be within the stated
limits under normal climatic conditions.
Spectral response of the Sunshine Pyranometer
(thermopile, diffusers and dome combined),
shown with the solar spectrum at ground level.
SPN1 Spectral response
0
20
40
60
80
100
120
0 500 1000 1500 2000 2500 3000
W avelength nm
relative contributi
o
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
Solar
SPN1
Overall accuracy: Total
(Global) radiation and
Diffuse radiation
±5% Daily integrals
±5% ±10 W.m-2 Hourly averages
±8% ±10 W.m-2 individual readings
Resolution 0.6 W.m-2 = 0.6mV
Range 0 to >2000 W.m-2
Analogue output sensitivity 1mV = 1 W.m-2
Analogue output range 0-2500mV
Sunshine status threshold 200 W.m-2 in the direct beam
Other specifications
Accuracy: Sunshine status ±10% sun hours
with respect to the threshold
Accuracy: Cosine Correction ±2% of incoming radiation
over 0-90° Zenith angle
Accuracy: Azimuth angle ±5% over 360°rotation
Temperature coefficient ±0.02 % /°C typical
Temperature range -20 to + 70°C
Stability Recalibrate every 2 years.
Typical cosine response of the Sunshine Pyranometer
compared to the ideal cosine curve.
The upper curve shows the relative accuracy.
SPN1 Cosine response
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
0 102030405060708090
Zenith angle (degrees)
Ideal cosine
Absolute output
Relative error
2% limits
Response time < 200ms
Spectral Response 400-2700nm
Spectral sensitivity 10% typical
Non-linearity <1%
Tilt response negligible
Zero Offsets < 3W.m-2 for a change of 5°C/hour
in ambient temperature.
<3 W.m-2 dark reading
Latitude capability -90° to + 90°
Environmental: Sealing IP67
Sunshine status output No sun = open circuit
Sun = short circuit to ground
Power requirement 2mA (excluding heater power),
5V – 15V DC
Heater power 12V – 15V DC, up to 1.5 A
Heater control Continuously variable up to 20W
output for external temperatures
below 0°C
Lowest snow & ice-free
temperatures
(using internal heater)
-20°C at 0 m/s wind speed
-10°C at 2 m/s wind speed
Mounting options: 3 x M5 tapped holes in base;
108mm pcd, 120°spacing
Size & Weight 140mm dia x 100mm high, 786 gm
Notices
Patents: The SPN1 Sunshine Pyranometer is protected by patents EP1012633 & US 6417500.
EMC certification: available on request.
Delta-T Devices Ltd
128 Low Road, Burwell, Cambridge,CB25 0EJ, UK
Tel: [phone] Fax: [phone]
email: [e-mail] web: www.delta-t.co.uk
All manuals and user guides at all-guides.com