Lufft SHM31 User Manual

Item names and technical data
8 Snow depth sensor SHM 31, V2.1
2.2. Technical data
Category
Name
Value
Measuring parameters
Snow depth
0 – 15 m
Accuracy
± (5 mm + 0.06%)
Repeatability
0.6 mm
Precision, reproducibility
5 mm
Signal intensity (normalised)
0 – 255
Installation
Assembly height / measuring
distance
0.1 – 16 m
Tilt angle to the vertical position
10 – 30 degrees
Data interface
RS485
- UMB binary protocol (19200 Bd, variable)
- UMB-ASCII 2.0
- Modbus RTU
- Modbus ASCII
SDI-12
- SDI-12 protocol
RS232
- UMB-ASCII 2.0 protocol (9600 Bd, fixed)
RS485 and SDI-12 share the same connectors and cannot be used in parallel. RS232 uses separate
connectors and can be operated in parallel with RS485 or SDI-12.
Data transfer
Polling: UMB, UMB-ASCII 2.0, SDI-12,
Modbus
Auto Send function: UMB-ASCII 2.0
Operating parameters
Temperature range:
Without heating:
-40°C – + 50°C
-10°C – +50°C (laser inactive < -15°C)
Rel. humidity
0 – 100%
Power supply
12 or 24 V DC, tolerance ±15%
Connected load with heating
18 W
Average consumption without
heating
0.7 W
Average consumption with 10 s
measurement interval and window
heating switched on
3.4 W
MTBF @ 25°C / 40°C
88,000 h / 50,000 h
Connection cable length while using
the RS232 interface
1
≤ 15 m
Safety
Laser safety
Laser Class 2 (IEC 60825-1:2014)
Protection rating
IP68
EMC
EN 61326-1:2012 (industrial standard)
EU Directive
EMC 2014/30/EU, ROHS 2011/65/EU
Size, weight
Sensor size (LxWxH)
302 x 130 x 234 mm
Sensor weight
2.35 kg
Packaging size
400 x 240 x 180 mm
Weight incl. packaging
3.4 kg
Storage conditions
Temperature; rel. humidity
T={-25°C – +70°C}; rH < 100%
Table 2 2: Technical data
1
If connection cables > 15 m are used, transfer problems may occur over RS232. Additionally, the voltage
drop over the cable length must be taken into account.

Lufft SHM31 Specifications

General

Brand	Lufft
Model	SHM31
Category	Accessories
Language	English