UP 500 english - SNT Sensortechnik AG

SONARANGE 

Ultrasonic Distance Sensors 

especially for use where other sensors 

have given up 

Series 

UP 500 

UP 1000 



UP 5000 

Detection range 80...5000 mm 

Detection and distance measurement unaffected by target material 

Extremly high reception sensitivity (e.g. UP 500/1000) 

Detection of very small and poorly reflecting objects 

Resolution + -–1.5.... + – 3 mm (acc. to model) 

Analogue voltage and current outputs (also inverted) 

Measuring and switching outputs in one unit 

Switching rate 2..30 Hz 

Models with adjustable zero and variable slope 

Options with 2 adjustable switching outputs 

Protection class IP 67, watertight, fully encapsulated, rugged transducer 

Small, cubic housing, easy to mount 

Excellent value 

THE ULTRASONIC PROFESSIONALS 

SNT SENSORTECHNIK AG

Why ultrasonic sensors 

Ultrasonic sensors have many advantages over 

optical, inductive, capacitive and magnetic 

switches. 

• They can sense any material. With a few exceptions, 

all objects can be detected equally well so long as a 

certain minimum size and a certain maximum angle of 

incidence are maintained. 

• No correction factors have to be applied (as with 

inductive sensors, for example). Colour does not matter. 

The surface of the scanned objects has no influence on 

the measuring accuracy. Only the maximum permitted 

angle of incidence is affected by the surface roughness. 

• They function in fog, dust, dirt or extreme lighting. These 

create problems for many optical sensors. 

• Ultrasonic sensors are very good at detecting transparent 

(and shiny) objects (foil, panes of glass, bottles, etc.). 

Optical sensors often emit double pulses. 

• They are able to disregard disturbing backgrounds 

(provided the right model is chosen). 

• US distance sensors can still detect small objects at 

considerable distances. (Here inductive and capacitive 

sensors fail completely.) 

• US distance sensors measure the distances to the 

targets with high linearity and over wide ranges. 

Where are the limits to using ultrasonic sensors 

• The system itself and the laws of physics (the speed of 

sound is 343 m/s in air at 20°C) mean that US sensors 

are relatively slow. The maximum switching rate with 

series UP 500 is 30 Hz, UP 5000 ca. 2 – 3 Hz. 

• For the same reasons, resolution is about + - 1.5 mm 

(assuming constant ambient conditions, carrier frequency 

185 kHz). UP 3000/5000 + - 3 mm. 

• They do not work under water, in a vacuum or at elevated 

pressures (their transmission medium is air at barometric 

pressure). 

• Ultrasonic distance sensors cannot be used where there 

is an explosion hazard. 

• They cannot detect very hot or very cold objects 

(turbulence in the transmission medium refracts and 

scatters the sound). 

Applications 

• Monitoring or measuring distance, regardless of 

target material 

• Controlling belt tension or sag 

• Measuring liquid level in small containers 

• Measuring water level in drains 

• Monitoring liquid level in bottling plants 

• Measuring roll diameter on reeling machines 

• Detecting the feed of strip stock to blanking 

machines and presses 

• Checking for tailbacks on conveyor belts 

• Recognising full or empty pallets 

• Monitoring the height of stacks 

• Preventing collisions on suspension conveyors 

• Monitoring the feed rate of binding agents in oil 

separators 

• Detecting transparent objects, foil, flat glass, 

bottles, etc. 

• Access supervision at rotating doors, counters, etc. 

• Sensing objects in robot grippers 

• Collision avoidance on driverless vehicles 

• Measuring the volume of tree-trunks 

• Determining the dimensions of packages 

• Distance monitoring on combine harvesters, beet 

lifters, etc. 

• Monitoring ground clearance on pesticide sprayer 

booms 

• Sensing cut length on automatic drawing machines 

• Vehicle reverse warning systems 

• Monitoring the level of inert gases (argon, 

nitrogen etc.) in small containers 

• Sensing the height of plants in automated 

greenhouses 

• Scanning the profile of human limbs (checking the 

effectiveness of treatment for vein ailments) 

• Measuring level in printing-ink mills/tanks 

• Measuring coil diameter while unreeling cable 

• Sensing and signalling valve positions 

• Checking drums, baskets and trays in electroplating 

plants 

• Counting onlookers at freestanding sales displays 

or showcases 

• Checking residues in bottles for recycling 

• Monitoring contents of granulate hoppers on 

injection moulding machines 

2

Operating principle 

Through carefully considered use of the latest technologies, 

SNT Sensortechnik AG has successfully developed miniature 

high performance ultrasonic sensors which in a very 

small space can do things that much bigger sensors have 

so far been incapable of. 

Depending on the model, the composite ultrasound transducer 

generates ultrasonic waves with a frequency of about 

185 kHz (UP 3000/5000 = 90 kHz) and emits them in 

bursts at a constant rate (UP 500 = 120 Hz, UP 1000/2000 

= 60 Hz, UP 3000/5000 = 20 Hz). In the intervals between 

these bursts, the same transducer acts as a sound receiver 

with a pronounced directional characteristic. The scanned 

zone is lobe-shaped and relatively narrow (see diagrams). 

On the basis of measuring the transit time, the sound waves 

reflected from the target during the breaks in transmission 

are processed as echoes in the unit to produce an output 

signal proportional to the distance. With some models this 

signal is available as a voltage or a current. 

All models are equipped with a controlled input amplifier 

which makes sure that both small and large objects are 

detected with the same accuracy. 

The sensor’s binary output (transistor pnp, npn) is activated 

if the distance to a detected object is less than that set on a 

potentiometer. 

Some models have two separately adjustable outputs 

connected as normally open (NO) or normally closed (NC) 

contacts. 

Selected versions have a synchronising input, some 

together with a scan input. If several sensors are contained 

in a small area, these can then be controlled so as to 

minimise or completely eliminate any mutual interference. 

The sensors are supplied ready to connect. All that is needed 

to operate them is a suitable power supply (24 VDC). 

Choice of models 

UP 500 PVPS 24 IS (pnp), 

UP 500 PVNS 24 IS (npn) 

The sensors in this series are used for distances of about 

80 to 500 mm (distance range of analogue output up to 

800 mm). They have the highest sensitivity of all ultrasonic 

sensors and so are also suitable for detecting very small or 

extremely poorly reflecting targets (e.g. wire of 0.3 mm diameter). 

Their switching frequency is very high, and hence 

so is the tracking speed of the analogue voltage or current 

output (approx. 8 ms per 100 mm of travel). They can be 

used instead of optical devices in many cases (e.g. dirty 

locations). The sensors are delivered with a pnp or npn 

output (adjustable from 100 to 500 mm) and also an 

analogue output. (Options: output as NC contact, output 

current 4 – 20 mA, inverted analogue output, synchronisation, 

scan input, etc.) 

The version UP 500 PDPS 24 IS has two independent 

outputs adjustable between 100 and 500 mm (both outputs 

are pnp NO). In the similar version UP 500 PDPA 24 IS, one 

output is connected as pnp NO, the other as pnp NC. Very 

simple window functions are thus possible. Sensor UP 500 

PVOR 24 IS is provided with an adjustable zero (zero shift 0 

to 100 mm, e.g. distance 100 mm = 0 volts) and adjustable 

slope (factor 1 to 5, e.g. distance 100 mm = output voltage 

5 volts). Altering the zero and the slope (span), however, 

also influences the switching point of the logic output and 

the hysteresis. This sensor allows the output voltage to be 

adapted to the local conditions, within certain limits. 

UP 1000 PVPS 24 IS (pnp), 

UP 1000 PVNS 24 IS (npn) 

With a distance range of 200 - 1000 mm, this series covers a 

great many applications. The reception sensitivity (the ability 

to detect small or poorly reflecting objects) is very high, so 

practically any target can be sensed right up to the maximum 

distance. With 8 imp. a second when ideally set, the 

switching frequency is about average for the sensors overall, 

while the tracking speed of 15 ms per 100 mm travel is still 

relatively fast. These sensors are available with pnp or npn 

switching outputs and an analogue output voltage of 0 to 

+10 V. Options include an inverted analogue output, output 

currents of 4 – 20 mA, synchronisation and scan inputs. 

Special versions to order. 

Version UP 1000 PDPS 24 IS is equipped with two NO outputs 

separately adjustable for distances of 200 to 1000 mm. 

The virtually identical version UP 1000 PDPA 24 IS has one 

NC output and one NO output. 

Sensor UP 1000 PVOR 24 IS is provided with an adjustable 

zero (zero shift 0 to 200 mm, e.g. distance 200 mm = 0 volts) 

and adjustable slope (factor 1 to 5, e.g. distance 200 mm 

= output voltage 10 volts). Altering the zero and the slope 

(span), however, also influences the switching point of the 

logic output and the hysteresis. This sensor allows the output 

voltage to be adapted to local conditions, within certain 

limits. 



The sensors of this series have an extended range from 400 

up to 2000 mm. Despite the long distance, the carrier 

frequency is still around 180 kHz (like models UP 500/1000). 

This makes them completely immune to extraneous noise, 

and yet the scanned zone is still relatively narrow. They are of 

middling sensitivity (25 cm 2 ) and so are able to detect quite 

small, moderately reflecting objects. At 3 imp. per second, 

however, their switching frequency is comparatively low. The 

analogue output’s tracking speed of 100 ms per 100 mm 

travel is also comparatively slow, but adequate for most 

applications. 

The sensors have pnp or npn outputs and an analogue 

output voltage of 0 to +10 V. Obtainable as options are 

output current 4 – 20 mA, inverted output voltage +10 – 0, 

synchronisation and scan inputs. 

Version UP 2000 PDPS 24 IS has two NO outputs separately 

adjustable between 400 and 2000 mm. The virtually identical 

version UP 2000 PDPA 24 IS has one NC output and one 

NO output. 






logic output and the hysteresis. This sensor allows the 

output voltage to be adapted to local conditions, within 

certain limits. 

3



In contrast to the models described above, the sensors of 

this series operate with a carrier frequency of 90 kHz, which 

greatly reduces attenuation of the signal passing through 

air. This ensures that small or poorly reflecting targets can 

be detected at distances from 300 up to the maximum 

3000 mm. The scanned zone of these sensors is considerably 

wider than with the models described earlier. For physical 

reasons, the maximum attainable switching frequency is 

relatively low (2 – 3 imp. per second). This also applies to the 

tracking speed of the analogue output (100 ms per 100 mm 

travel). 

The sensors have a pnp or npn switching output and an analogue 

voltage output (0 to +10 V). Available options include 

output current 4..20 mA, inverted analogue output +10 – 0 V, 

synchronisation of the transmission cycle or scan input. 

Version UP 3000 PDPS 24 IS has two NO outputs separately 

adjustable between 300 and 3000 mm. The version UP 

3000 PDPA 24 IS is identical, but has one NC output and 

one NO output. The models with two outputs are used 

mainly for level-monitoring. 






logic output and the hysteresis. This sensor allows the 

output voltage to be adapted to local conditions, within 

certain limits. 

UP 5000 PVPS 24 IS (pnp), 

UP 5000 PVNS 24 IS (npn) 

Like the model UP 3000.. described above, these sensors 

operate with a carrier frequency of 90 kHz. Apart from the 

maximum response distance (5000 mm), the hysteresis and 

sensitivity are largely the same as for type UP 3000.. 

For scanning at the maximum distance, however, the 

sensitivity of about 500 cm 2 is significantly lower than with 

the UP 3000.. 

This model is used principally for monitoring the level of 

liquids. Again, these sensors have a pnp or npn switching 

output and an analogue voltage output (0 to +10 V). Options 

are an output current of 4 – 20 mA, inverted analogue output 

(+10 – 0 V), synchronisation or scan input. 

Other options supplied to order. Also available are a version 

with two pnp NO outputs separately adjustable from 500 to 

5000 mm (UP 5000 PDPS 24 IS) and a version with one NO 

and one NC output (UP 5000 PDPA 24 IS). 

Sensor UP 5000 PVOR 24 IS is provided with an adjustable 

zero (zero shift 0 to 500 mm, e.g. distance 500 mm = 0 volts) 


= output voltage 10 volts). Altering the zero and the slope, 

however, also influences the switching point of the logic 

output and the hysteresis. This sensor allows the output 

voltage to be adapted to local conditions, within certain 

limits. 

4

Summary of models 

Features 

Options 

Model 

UP 500 PVPS 24 IS 

UP 500 PVNS 24 IS 

UP 500 PVPS 24 IS I 

UP 500 PVPS 24 IS IV 

UP 500 PDPS 24 IS 

UP 500 PDPA 24 IS 

UP 500 PVOR 24 IS 

UP 1000 PVPS 24 IS 

UP 1000 PVNS 24 IS 

UP 1000 PVPS 24 IS I 

UP 1000 PVPS 24 IS IV 

UP 1000 PDPS 24 IS 

UP 1000 PDPA 24 IS 

UP 1000 PVOR 24 IS 















UP 5000 PVPS 24 IS 

UP 5000 PVNS 24 IS 

UP 5000 PVPS 24 IS I 

UP 5000 PVPS 24 IS IV 

UP 5000 PDPS 24 IS 

UP 5000 PDPA 24 IS 

UP 5000 PVOR 24 IS 

operating range (mm) 

detection sensitivity (cm 2 ) 

500 2 







1000 5 

1000 5 

1000 5 

1000 5 

1000 5 

1000 5 

1000 5 

2000 > 30 

2000 > 30 

2000 > 30 

2000 > 30 

2000 > 30 

2000 > 30 

2000 > 30 

3000 20 

3000 20 

3000 20 

3000 20 

3000 20 

3000 20 

3000 20 

5000 500 







Hysteresis axial (mm) 

ca. 25 

ca. 25 

ca. 25 

ca. 25 

ca. 25 

ca. 25 

ca. 25 

40 

40 

40 

40 

40 

40 

40 

80 

80 

80 

80 

80 

80 

80 

120 

120 

120 

120 

120 

120 

120 

250 

250 

250 

250 

250 

250 

250 

resolution (mm) 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-2 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

+-3 

speed binary output (imp./s) 

30 

30 

30 

30 

30 

30 

30 

8 

8 

8 

8 

8 

8 

8 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

3 

speed analogue output (ms/100 mm) 

8 

8 

8 

8 

8 

8 

8 

15 

15 

15 

15 

15 

15 

15 

80 

80 

80 

80 

80 

80 

80 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

carrier frequency (kHz) 

voltage output 0...5 Volt 




current loop 4..20 mA 

zero and span adjustable 

binary output pnp NO 

binary output npn NO 

2 binary outputs NO 

2 binary outputs NO/NC pnp 

connections (page 11) 

180 • 

K 

180 • 

• 

L 

180 • 

M 

180 

• • 

P 

180 

• N 

180 

• O 

180 • • 

K 

180 •• • 

K 

180 

• 

L 

180 • 

M 

180 

• • 

P 

180 • • N 

180 •••• • O 

180 • 

K 

180 

• 

K 

180 

• 

L 

180 • 

M 

180 

• • 

P 

180 • • N 

180 •••• • O 

180 • 

K 

90 

• 

K 

90 

• 

L 

90 • 

M 

90 

• • 

P 

90 • • N 

90 •••• • O 

90 • 

K 

90 

• 

K 

90 

• 

L 

90 • 

M 

90 

• • 

P 

90 • • N 

90 •• • O 

90 • • 

K 

Important! Standard delivery includes 1 bracket OPM 01 for UP 500, UP 1000, UP 2000, bracket UPM 09 for UP 3000, UP 5000, screws M4, 

rubber gasket for UP 3000 and UP 5000. 

Other versions and configurations supplied to order 

case style (page 6) 

see drawing 

V 

V 

V 

V 

VI 

VI 

VII 

V 

V 

V 

V 

VI 

VI 

VII 

V 

V 

V 

V 

VI 

VI 

VII 

VIII 

VIII 

VIII 

VIII 

IX 

IX 

X 

VIII 

VIII 

VIII 

VIII 

IX 

IX 

X 

5

Housings and controls 

Housing and controls type VI 

Transducer surface 

diameter 18 mm (UP 1000, UP 2000) 

11 mm (UP 500) 

Housing and controls type V 

Housing and controls type VII 

Housing and controls type IX 

Housing and controls type VIII 

Housing and controls type X 

6

Terms and definitions 

Detection ranges 

The sensors of series UP 500 to UP 5000 cover distances 

ranging from about 80 mm to 5000 mm (measured from the 

transducer face). 

The overall range of a sensor can be divided into three parts. 

Only the middle section is usable. The near (or «blind») part 

from 0 – 80 mm or so (UP 500) up to 0 – 500 mm (UP 5000) 

must be kept clear of obstacles. Dependable detection is not 

possible here. Targets with very good reflective properties 

can give the impression of being detected at close range, but 

in fact the response is to secondary or tertiary echoes, rather 

than the primary echo. 

Typical scanned zone 

Distance 

Scanned 

zone for small 

targets 

e.g.0.5 mm dia. 

80 mm dia. 

Minimum target size 

steel rod 500 mm long 

With some models, the far limit range (i.e. the part beyond 

the useful range) is available, subject to limitations (e.g. in the 

case of model UP 500.. the analogue output can be used up 

to about 800 mm). 

The binary switching output is effective only within the useful 

detection range. The response distance can be set to within 

the near range, but the switching output is then blocked. 

Hysteresis 

The difference between «on» and «off» response points in the 

axial direction is called hysteresis (Greek for lagging behind). 

It is necessary for correct response behaviour. 

The axial hysteresis is preset for each kind of sensor (see 

Technical data). The radial hysteresis is not defined, but is 

very small. The response distance must always be set on the 

potentiometer so that when the target object is removed 

there is no background obstruction within the hysteresis 

band (otherwise, having responded the first time, the output 

will stay permanently «on»). 

Scanned zones, target size 


Distance 

Scanned 

zone for targets 

> 10 cm 2 

Analogue output up to 900 mm 

Ambient temperature + 20° C 

Scanned 


targets 

e.g. 1 mm dia. 

160 mm dia. 

Scanned 


> 20 cm 2 

(at exact right angle to beam axis) 



The scanned zones of all the sensors described in this 

booklet are lobe-shaped, but the shapes vary according to 

model. With very small targets the form of the scanned zone 

is different from that with large objects. The measurements 

on which the diagrams are based were carried out with 

medium-sized to large target objects. In each case the scanned 

surface was at right angles to the beam axis (ambient 

temperature +20°C; at higher temperatures the sensitivity is 

somewhat reduced). 

As a general rule, a large surface area increases the certainty 

of detecting the object, but has scarcely any effect on the 

measuring accuracy. In other words, large and small targets 

are detected at the same point and produce the same 

analogue output voltage. The only exception to this is a very 

small object located immediately in front of a highly reflective 

surface, such as a needle at a distance of 80 mm from a 

sheet of metal. The control amplifier contained in the sensor 

adjusts itself to the reflections from the background and so 

suppresses the weak echoes from the needle. This effect 

can be eliminated by tilting the sensor. 

The sensitivity of SNT sensors, i.e. the ability to detect very 

small or poorly reflecting objects, is higher than that of most 

competing products. 



Distance 

Scanned 


targets 

e.g. 2 mm dia. 

220 mm dia. 

Scanned 


> 25 cm 2 

(at exact right angle to beam axis) 




7

Typical scanned zone Minimum target size 

steel rod 500 – 1000 mm long 

Forbidden range 

Properties of the scanned object 

At room temperature, practically any object can be detected 

within the useful range, provided it is of a certain minimum 

size. The exceptions are highly sound-absorbent objects and 

materials (loose cotton, felt, open-pored foam rubber and 

certain textiles, etc.). These can either not be detected at all, 

or not over the full useful range. 

Hot or very cold objects (temperature difference from 

ambient > 60 degrees) cause severe shimmer in the transmission 

medium air, upsetting propagation of the sound. 

Reliable detection is not possible. This also applies to 

articles emitting a lot of gas (e.g. liquids, propellant-foamed 

items, etc.). 

Preliminary trials are necessary in doubtful cases. 


3000 mm 

distance 

Inclination of target surfaces to beam axis 

As with optical systems, if the angle deviates too far from 

perpendicular to the beam axis, insufficient signal is reflected 

back to the receiver. 

This physical effect can be largely overcome by adjusting 

the system, but it can happen that very small targets can 

be detected only within an angle of 7 degrees. With models 

UP 500/1000 for example, larger or rough objects 

(roughness depth greater than 1.6 mm) can be angled 

at more than 60 degrees with no loss of performance. 



steel rod 500 – 1000 mm long 

Forbidden range 

Switching rate 

For physical reasons, ultrasonic sensors react more slowly 

than, for example, optical or inductive devices. The speed of 

sound in air is 343 m/s at 20° C, and this limits the sensors’ 

speed of response. Sensors with extended useful ranges, 

such as UP 3000/UP 5000, are by their nature much slower 

than sensors for shorter distances (e.g. UP 500). 

This fact must be borne in mind particularly when sensors 

are used for detecting fast-moving targets. Here the time for 

which the target remains within the sonic beam is important 

(see Technical data). 


8

Synchronisation (option) 

When several sensors with the same carrier frequency are 

operated at the same location, they can interfere with each 

other (indicated by rhythmical switching of the binary output 

or a fluctuating analogue signal). Detection is normally no 

longer possible. This phenomenon is found with all ultrasonic 

distance sensors. By synchronising the transmission 

cycles of all the sensors involved (up to 15 sensors of the 

same type), one can substantially reduce or even eliminate 

the otherwise necessary minimum clearance between them. 

Any mutual interference is largely avoided in this way. 

To synchronise the sensors concerned, the synchronisation 

inputs of all of them must be linked by a screened cable 

as short as possible. 

As all the sensors then transmit simultaneously, the peak 

power requirement is correspondingly higher. The power 

supply must be able to meet this demand. The continuous 

current per sensor is about 60–70 mA (without load), but the 

peak current is roughly 0.8 A. A back-up capacitor of 1000 

uF 35 V in parallel with the power supply is suitable for 

supplying the peak current. 

Scanning, multiplexing (option) 

Some models are available with a Scan input. If this is 

connected to the negative side of the power supply (current 

about 20 mA), transmission and reception are inhibited. The 

measured values (analogue output) are stored only briefly, 

and if required the binary output is reset. 

The enable time is approximately 200 ms and the scan rate 

is about 4 Hz (UP 500). An additional waiting time of 30 ms 

or so should be included in order to avoid overlapping. 

Scanning and synchronisation can be combined, but there 

is little point unless the detection process is very slow. 

MEK may be used with great care (not repeatedly), so long 

as it is dried off immediately. 

Strongly alkaline agents and very hot water or steam should 

not be used for cleaning. 

Abrasive treatment of the transducer face will alter its 

acoustic properties and can result in permanently reduced 

sensitivity. 

Sensors with a carrier frequency of 180 kHz are not affected 

by extraneous sound sources (except other ultrasonic 

sensors). The performance of sensors with a 90 kHz carrier 

frequency may be impaired if strong sound sources are 

located within the scanned lobe or on a line with it in the 

axial direction. 

Very strong airflows (>20 m/s), either hot or cold, across the 

beam direction can adversely affect the certainty of detection. 

The usual air movements in buildings, etc. have hardly 

any influence. 

The housings of these ultrasonic sensors are made of glassfibre-reinforced 

polyamides, epoxys and neoprene rubber. 

The cables are covered with PVC (other materials to order). 

These materials are bonded together with cyanoacrylates, 

epoxys and polyurethanes. All these substances can be 

attacked by solvents, acids, alkalis and other chemicals. If 

required, sensors can be supplied with coatings specifically 

against these agents. 

The sensors conform to protection class IP 67. They are 

fully encapsulated and therefore dusttight and watertight. 

However, they cannot be used in water. 

Environmental factors 

Although ultrasonic distance sensors are relatively immune 

to their surroundings, a few points should be noted. 

The speed of sound in air varies with temperature. It rises 

by 0.17%/deg C. A change in temperature thus causes an 

uncompensated error; the measured position of the target 

is shifted slightly. 

Very large temperature differences (>50°C) along the 

measured range can diffract and scatter the sound. 

Measurement may be incorrect or even impossible. 

Changes in atmospheric air pressure have little effect, but 

operation in a pressurised environment results in spurious 

readings. In a vacuum, of course, sound cannot travel at all 

In normal use the influence of humidity is negligible. 

If condensation does occur, the worst that can happen is a 

slight temporary drop in sensitivity. (SNT can supply sensors 

specially coated to shed droplets easily.) Ice must not form 

on the transducer face. 

The sensors comply with the relevant standards on electromagnetic 

compatibility. Noise immunity accords with IEC 

801-2 (4 kV/8 kV crit. B), IEC 801-3 (3 V/m crit. A) and IEC 

801-4 (1 kV/2 kV crit. B). If interference is extremely severe, 

the sensor mountings should be insulated (without using 

metal parts). The negative power lead should be earthed 

wherever possible, or connected to the machine frame. 

(see bottom diagram on next page) 

Loose particles (dust, dirt) on the transducer face are no 

problem. 

The transducer face must not be painted. 

For cleaning, use only mild, water-based agents, or briefly 

alcohol. In the event of severe fouling, trichloroethane or 

9

Installation 

The sensors can generally be mounted in any position. 

Attention should be paid to the following points, however. 

Two sensors must not be mounted directly facing each other. 

This can create problems even at several times the useful 

range. 

Two sensors must not scan the same target (although this 

is possible with synchronised units). 

The minimum space between two sensors mounted next to 

each other is best found by experimenting. Synchronised 

sensors can be installed very close together. 

Sensors of series UP 500 and UP 1000 are extremely sensitive 

and will therefore respond to even the smallest bumps, 

holes or screwheads on surfaces oblique to the beam axis. 

Sensor 

Mounting in narrow pipes can cause difficulties. The inside 

diameter of the pipe should be at least three times the diameter 

of the sound beam. The pipe must not contain any projecting 

parts, holes or deposits. Realistic trials are advisable. 

The transducer cases of series UP 500/1000/2000 must 

always be completely unobstructed. 

Deposits etc. 

Transducer 

Rubber gasket 

UPGO 431 

Machine frame 

Transducer 

clear 

Keep 

Container wall 

Liquid 

Projecting parts 

Distance from 

Container wall 

Direct attachment to metal parts is not possible. The rubber 

gaskets UPGO 431 supplied must be used with sensors 

UP 3000/5000. This prevents the sound from being transferred 

to metal components (plates, brackets, girders, etc.). 

If these instructions are disregarded, the binary output may 

be permanently activated and the analogue output may 

persistently carry a low reading of perhaps 1.6 V. 

Sensor 

Power supply 

Outputs 

Screen 

Machine frame 

Insulation 

The earth connection 

to 0 V is optional 

10

Connections 

These ultrasonic sensors can be operated from any DC 

power supply that satisfies the minimum requirements for 

noise-signal emission and safety. Conventional power units 

are preferable to cheap switched-mode equipment. 

Ultrasonic distance sensors have a power consumption 

of some 60–70 mA, but the power supply must be able to 

handle a peak current of about 0.8 A (peaks last about 

100 µs, repetitive in transmission cycle). If the leads are long 

or of small cross-section, the current spikes will result in 

corresponding voltage drops on the negative line to the 

power supply. These are of the order of 50 to 500 mV, 

depending on the wire’s length and thickness. If this causes 

problems, a back-up capacitor must be fitted directly at the 

sensor, or a separate measuring earth to the evaluation 

circuit provided. (Back-up capacitor of e.g. 220 µF 35 V, 

in parallel with the power supply line.) 

The wires of the sensors are delivered with the ends tinned. 

We recommend replacing the tinned ends with ferrules. 

Outputs 

The sensors have transistor outputs with open collector. 

The standard output is a pnp normally open (NO) contact 

which delivers a voltage U = Us – 3 V (usually 21 VDC or 

more) when the response distance is less than the set value 

(load current 0.1 A). 

Also available on some models are npn NO or pnp NC 

contacts. All binary outputs are short-circuit-proof and their 

power is monitored (the output current may therefore briefly 

rise to 0.5 A max., 20 % duty factor). 

output pnp 

output npn 

(option) 

analogue 

output 

screen 

11

The analogue outputs are either voltage outputs of 0 to +5 V 

or 0 to +10 V, or impressed-current outputs of 4 to 20 mA 

(inverted versions, e.g. +10 to 0 V, are available in both 

cases). The relationship between distance and output signal 

can be seen from the two diagrams. The load on the voltage 

outputs should not exceed 1 mA. The voltage outputs are 

short-circuit-proof, but must not be subjected to any external 

voltage. The current outputs can be operated with a load 

resistance of 0 to 500 ohms. 

The dynamic response of the analogue outputs is shown in 

the diagram below. If there is no target, the output signal 

stays at about +14 V (A). With model UP 500 this is about 

9.8 V. In the example illustrated, an object enters the scanned 

area at a distance of 300 mm, and within a few system 

cycles (8.3 to 50 ms per cycle, depending on model) the 

output signal drops to +3 V (B). On a further change in 

distance, e.g. to 800 mm, the output signal reacts fairly 

quickly (C). But if the target leaves the scanned zone 

completely, the output voltage of the model in question goes 

back within a few seconds to +14 V, and stays there (D). 

The current outputs behave in the same way. Special slow 

versions are obtainable on request. 

Transmit cycle 

12

Technical data 

System UP 500.. UP 1000.. UP 2000.. UP 3000.. UP 5000.. 

Scanning range (standard target ca. 100..500 cm 2 , 

right angle to beam) ca. 80..500 mm 200..1000 mm 400..2000 mm 300..3000 mm 500..5000 mm 

Response distance 

adjustable with 1-turn potentiometer 

Hysteresis axial (radial not defined) ca. 25 mm ca. 40 mm ca. 80 mm ca. 120mm ca. 250 mm 

Reproducibility of response point 

ca. 1% (30 min. after switch-on, 22°C) 

Linearity of analogue voltage output 

ca. + - 1,5 % (Sn max., calibration at 0,5 Sn) 

Linearity of optional current output ca. + - 2 % (Sn max., calibration at 0,5 Sn) 

Accuracy, absolute 

ca. + - 2 % for all models at calibration point 0,5 x Sn 

Resolution (typical) 2 mm 2 mm 2 mm 3 mm 3 mm 

Temperature sensitivity (analogue output) 

Temperature sensitivity of air path 

Start-up drift 

ca. + 8 mV/K (sensor only, not air path) 

ca. + 0.17%/K 

ca. 100 mV 

Response sensitivity (see diagrams) ca. 2 cm 2 ca. 5 cm 2 > 30 cm 2 20 cm 2 500 cm 2 

(min. target area required for sure detection) 

Angle of detection cone (see also diagrams) ca 10° ca. 15° ca. 12° ca. 12° ca. 12° 

(for smallish targets, the angle can be considerably 

wider with large, well-reflecting objects) 

Transmission (Carrier) frequency ca. 180 kHz ca. 180 kHz ca. 180 kHz ca. 90 kHz ca. 90 kHz 

Outputs 

Binary output 

transistor, open collector, pnp (npn) max 0.1 A, short-circuit-proof, 

voltage drop approx. 3 V at 0.1 A 

usually a normally open contact is provided, models with suffix «D», e.g. 

UP 1000 PDPS 24 IS have 2 outputs (normally open), versions with added 

suffix «A», e.g. UP 1000 PDPA 24 IS have one normally closed and 

one normally open contact as the binary output 

Switching rate (max.) ca. 20..30 Hz ca. 8 Hz ca. 3 Hz ca. 2..3 Hz ca 2..3 Hz 

(depends on distance setting) 

Status indication 

red LED for 1st output (additional green LED for optional 2nd output) 

Analogue voltage output (typ.) ca. 0.80..+ 5 V 1.6..+10 V 1.6..+10 V 1.6..+10 V 1.6..+10 V 

Owing to the limit on useful range, 0 V can be reached 

only by versions with zero adjustment 

(e.g. UP 1000 PVOR 24 IS) 

(inverted voltage outputs available 

as option, suffix «IV») 

Residual ripple typ. 50 mV typ. 80 mV typ. 100 mV typ. 120 mV typ. 150 mV 

lead length 2 m 

Analogue current output 

(not available with all options) 

4...20 mA impressed, RL max. 500 Ohm, usable range ca. 6.5 mA..20 mA 

Tracking speed of analogue outputs 8 ms 15 ms ca. 60 ms 100 ms ca. 100 ms 

(in ms/100 mm of distance variation) 

Power supply 

Voltage range 18...35 VDC 18...35 VDC 18...35 VDC 18...30 VDC 18...30 VDC 

Consumption (at Us 24 VDC) ca 70 mA ca. 70 mA ca. 70 mA ca. 60 mA ca. 60 mA 

(switched, but without load current) 

Ripple max. 10 % 

Polarity reversal protection 

yes 

13

Options and auxiliary inputs 

Synchronisation inputs (option «SY») 

(supplied to order) 

Scan inputs (option «Y») 

(supplied to order) 

Zero shift and slope (span) adjustment 

(option «OR», in standard product range) 

The synchronisation inputs of up to 15 sensors of the same version can be 

linked together, so phase-locking the transmission cycles of all the sensors. 

The line between sensors must be short and screened. 

(Ri of input approx. 40 kOhm) 

Unused inputs must be insulated to avoid short circuits. 

By connecting this input to 0 V, transmission is interrupted and the receiver is 

disabled. (The status of the outputs changes at the same time.) 

The current to earth is approx. 20 mA. Scan resonse delay approx. 30 ms. 

Scan enable time approx. 200 ms, Scan rate approx. 4/sec. 

Unused inputs must be insulated to avoid short circuits. 

Versions with the suffix «OR» (e.g. UP 1000 PVOR 24 IS) have additional 

potentiometers for adjusting the zero offset and the slope (span) of the analogue 

output voltage. In this way the output voltage at 200 mm, for instance, 

can be set to 0 V. 

The slope can be varied with the built-in potentiometers by a factor of up to 5. 

In this way the output voltage at 500 mm can be set to 10 V, for example. 

(Both examples relate to UP 1000 PVOR 24 IS.) 

Ambient conditions 

EMC noise immunity 

ESD to IEC 801-2: 4 kV contact discharge or 8 kV air discharge at housing, 

criterion B 

RF fields to IEC 801-3: 3 V/m 27-500 MHz, criterion A 

Transient bursts to IEC 801-4: 1 kV/2 kV, criterion B 

Working temperature 

Storage temperature 

Pressure 

Humidity 

Protection class 

Explosion-proof 

- 10° C...+ 50° C (263K..323K) 

- 20° C...+ 70° C (253K..343K) 

atmospheric, approx. 900..1100 mbar 

Operation under vacuum or positive pressure not possible, or only with altered 

response distances and analogue output voltages. Calibration in air at atmospheric 

pressure. Operation in other gaseous media is possible with altered values. 

up to 99% r.h., no icing 

IP 67, fully encapsulated (polyurethane) 

no 

Housing 

Dimensions 

Materials 

Weight 

Connections 

Cable 

Accessories 

see diagrams 

polyamide (with approx. 15% glass fibre), mounting bushes 2 x M4 brass 

transducer: epoxy, Neoprene rubber, various adhesives 

based on cyanoacrylate. 

Transducers with water-repellent coating (PTFE) are available. 

approx. 250..300 gr, according to version 

see diagram 

2 m PVC, 4-6 wire, screened (other length or materials to order) 

Mounting bracket OPM 01 for UP 500/1000/2000 incl. 2 x M4 screws and washers 

Mounting bracket UPM 09 for UP 3000/5000 incl. 4 x M4 screws and washers 

Rubber gasket for UP 3000/UP 5000: UPGO 431 is supplied as standard 

These data are subject to change without notice. 

Caution! Ultrasonic sensors emit high sound levels. This may disturb animals with correspondingly acute hearing ( e.g. dogs, bats etc.). 

However, evidence of damaged hearing has not been observed to date. 

Human hearing is not adversely affected by such high frequencies (90 and 180 kHz). 

14

UP 500 english - SNT Sensortechnik AG

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