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Ordering questions

When will my order be confirmed?

The order is accepted and confirmed by us as soon as you receive an order confirmation from us.

Do you offer project discounts for large orders or projects?

For each request, we check whether we can grant a discount and, if so, at what level. This depends on many factors, and cannot be calculated on a global basis.

When will my order be delivered or shipped?

Our order confirmations always show the week in which the goods will be dispatched. For example, the dispatch date is week 12.

How do you handle complaints?

If you make a claim on one of our products during the warranty period, please send us an e-mail so that we can register the process in good time. You will then receive a 'REKL-Dxxxxx' number from our team. Please use this number to return the goods to our warehouse (Thurn-und-Taxis-Str. 22, 90411 Nürnberg). Further details can be found in our warranty conditions.

Comment les frais d'impression & de vernissage sont-ils calculés ?

Costs consist of two parts: 1. preparation costs (fixed price) and 2. printing/varnishing costs per part. Where applicable, the fixed discount is deducted from the printing/varnishing costs.
Example: 25 units are to be painted in RAL 9005.
Preparation costs: € 167.28 (fixed price)
Painting costs: € 16.11 x 25 minus 10% discount
Find out more about the different prices for varnishing and printing in our catalog.

Questions about connection & wiring

What is the difference between 2- and 3-wire connection (e.g. for PREMASGARD 21xx and 11xx pressure sensors)?

With a 2-wire connection, you only need to connect two cables (24V and output) to start up the device. In the case of a 3-wire connection, GND must also be connected to ensure error-free operation.

I need a 3-wire connection for passive devices. What type of device do I need?

A model with a 4-wire connection. All S+S detectors can be ordered in a 4-wire version as an option (if not standard). If only three wires are required, simply leave the fourth open (unconnected). The device will still work without a hitch.

Humidity

What's the difference between absolute humidity and relative humidity?

Air humidity is the water vapor content of air. The higher the temperature, the more water vapor the air can hold. This is why the maximum possible or absolute humidity is higher in warm air or at summer temperatures than in cold air or at winter temperatures. Absolute humidity is expressed in grams of water vapor per cubic meter of air (g/m³). Relative humidity (RH), on the other hand, refers to the percentage of actual water vapour in the air in relation to the maximum possible value.

Our multi-functional humidity and temperature sensors in the HYGRASGARD product range can calculate other output quantities from the measured relative humidity, such as dew point, mixing ratio and enthalpy.

What is the dew point?

Air can absorb more moisture as temperature rises. The degree of saturation is indicated as a percentage, see relative humidity. As the air cools, its relative humidity increases until it reaches, if necessary, its absolute absorption capacity of 100 percent water vapor, or the dew point. If cooling continues, excess water vapour is produced, which is deposited as dew or condensation.

HYGRASREG dew point sensors detect when the dew point is reached. Combined with heating or ventilation systems, this prevents dew from forming on the surfaces of cooling ceilings, pipes, etc. Our HYGRASGARD multifunctional detection devices with humidity and temperature sensors calculate the dew point from the relative humidity and air temperature detected.

What does prodynamic transverse convection mean?

Conventional dew point sensors measure condensation on an interface, such as pipes, heat exchangers or concrete ceilings, using a humidity probe placed in a channel along the interface. But that's not enough to prevent condensation. With S+S's patented principle of prodynamic transverse convection, the humidity probe is additionally bathed by a cross-current of ambient air, which enters through an opening perpendicular to the channel. This enables dynamic, real-time detection of the risk of condensation occurring if the dew point at the interface is not reached. In this way, a fan can be switched on via a connected controller to dry out the condensing humidity.

HYGRASREG dew point controllers from S+S all operate on the principle of pro-dynamic transverse convection.

What is the enthalpy of moist air?

In the case of moist air, enthalpy is the heat content resulting from the combination of the heat content of the dry part of the air and the heat content of the water vapor contained in the air. Enthalpy gives an indication of a system's potential heat release and is measured in kJ/kg. In room temperature control, it is considered a parameter of the climate of well-being.

Our multifunctional HYGRASGARD with humidity and temperature sensor calculate enthalpy from the relative humidity and air temperature detected.

What is the air mixing ratio?

The mixing ratio is the independent quotient of the mass of water vapor by the mass of water vapor-free air in a volume. It is measured in g/kg and is an important variable for regulating heating, ventilation, refrigeration and air-conditioning systems.
Our HYGRASGARD multifunctional detection devices with humidity and temperature sensors calculate the mixing ratio from the relative humidity and air temperature detected.

Temperature

Why do passive temperature sensors show discrepancies?

As non-active measuring elements, passive temperature sensors do not themselves emit a current or voltage signal corresponding to the detected temperature. Instead, connected control or regulating devices can call up the electrical resistance value of the measuring element. However, this is affected not only by temperature, but also by the resistance of the connecting cable and contacts. For some types of sensor, such as the PT100, this can have a considerable influence on the accuracy of the measurement.

To compensate for deviations caused by cable and contact resistance, our passive THERMASGARD devices must have this eliminated from the measured value, either manually or via the controller. On our active THERMASGARD transducers, line compensation is performed internally by the electrical circuit.

What is room climate, and how can we measure well-being or the 'climate of well-being' in rooms?

The indoor climate depends on a number of measurable variables, such as air temperature and humidity, pollutant content (VOCs, CO2, fine dust), lighting (light temperature) and noise, which can be influenced and regulated in a targeted manner. The values measured for these parameters vary greatly from person to person, and also depend on physical activity, current health and the time of day and season.

Regulated ventilation is considered the key to a healthy indoor climate with sufficient warmth, humidity and as few harmful substances as possible. The multifunctional AERASGARD air quality sensors control these parameters and enable controlled climate control, tailored to subjective well-being. PHOTASGARD brightness sensors and KINASGARD motion sensors can contribute to a climate of well-being with controlled lighting and shading.

Pressure

What does differential pressure mean?

Pressure difference refers to the difference between two pressures. Pressure transducers that indicate this difference as a measured variable or differential pressure must therefore measure two different pressures. Differential pressure measurement is used, for example, in filter monitoring or to determine volumetric flow.

PREMASGARD pressure sensors from S+S can measure both relative and absolute pressures, as well as differential pressures. A piezoresistive measuring element ensures maximum accuracy.

What is piezoresistivity and what are its advantages for pressure sensors?

Piezoresistive measuring elements use the interaction, discovered by the Curie brothers, between electrical voltage in a solid body and mechanical pressure exerted on it. The term is derived from the ancient Greek 'piezein' (to crush, to compress). The piezoresistive effect describes the modification of electrical resistance by pressure, and enables highly accurate pressure detection.

PREMASGARD pressure sensors from S+S all work with a piezoresistive measuring element.

Air quality

What are VOCs and mixed gases?

Volatile organic compounds (VOCs) or mixed gases are volatile organic compounds that evaporate easily and can have a decisive impact on people's well-being and health. Known syndromes range from fatigue and headaches to eye irritation and dizziness. Unlike the CO2 content of ambient air, most VOCs are perceptible to humans by smell, although "pleasant-smelling" VOCs can be potentially hazardous to health. Typical sources of VOCs include floor and wall coverings, varnishes and adhesives, furniture and office equipment, but also plants, cleaning products and perfumes.

Our AERASGARD air quality sensors detect the VOC content in ambient air using a measuring element that reacts to the VOC molecules present on its surface, and is only slightly sensitive to potentially disruptive influences such as air temperature and humidity. The VOC content of the ambient air, expressed as a percentage, serves as a measurement variable for room climate. At VOC levels of 60% and above, it is advisable to ventilate the room.

Why measure CO2 in buildings?

Carbon dioxide (CO2) is a colorless, odorless gaseous compound of carbon and oxygen, present at around 0.04% (400 ppm) in natural air. CO2 is released both during combustion of carbon-containing materials and during exhalation. When the CO2 content of ambient air is too high, both well-being and ability to concentrate decline. CO2 content is also regarded as a surrogate indicator of the proportion of potentially virus-carrying aerosols in premises. Measuring the CO2 value therefore serves as a basis for the timely supply of fresh air to prevent such risks. The recommended threshold value for ventilation is 1000 ppm.
AERASGARD air quality sensors for CO2 work with a non-dispersive infrared sensor that uses the attenuation property of CO2 for light in the 4.26 µm wavelength range to determine the CO2 concentration, see NDIR technology.

How does non-dispersive infrared (NDIR) technology work in CO2 measurement?

NDIR sensors for CO2 consist of a measuring system with a light source, a measuring section and a receiver with filter. The filter is calibrated so that it only lets through light in the 4.26 µm wavelength range, which in turn is typically attenuated by CO2 molecules along the measuring section. The sensor determines this attenuation and converts it into ppm CO2.

All S+S AERASGARD CO2 air quality probes are equipped with a long-life NDIR sensor that automatically recalibrates at regular intervals to the base value of 400 ppm (normal CO2 content in outdoor air). They detect CO2 concentration in ambient air up to values of 3000 to 5000 ppm.

Why can't my CO2 sensor detect mixed gases (VOCs) and my VOC sensor detect CO2?

Since an NDIR sensor for CO2 selectively measures only the attenuation of light by CO2 molecules, it cannot detect VOC molecules. CO2 is an inorganic compound. A VOC sensor, on the other hand, only reacts to mixed organic gases and therefore does not detect CO2 molecules.

However, both values - CO2 and VOC content - are generally decisive for the well-being climate in rooms. Approaches aimed at converting or deducting the two values from each other have proved ineffective in practice and are considered irritating. That's why the AERASGARD range of air quality sensors from S+S includes several multifunctional devices equipped with both an NDIR sensor for CO2 and a sensor for VOCs.

What is fine dust?

Dusts are distinguished by standardized particle sizes as coarse, fine and ultrafine. Particulate matter (PM) is inhalable dust with an aerodynamic particle diameter of less than 10 µm. The international designation PM10 has been adopted for this purpose. Respirable fine dusts are present from 2.5 µm or less (PM2.5) and ultrafine dusts from 0.1 µm or less.

Fine dust in premises comes from oil and wood heating, tobacco smoke and asbestos, unfiltered vacuum cleaners and toner from photocopiers or laser printers, as well as from fungal spores and plants. It can cause cardiovascular disease, cancer and acute and chronic respiratory illness. For outdoor air, the European Union prescribes a maximum average value of 50 µg/m³ over 24 hours. However, inside buildings, values are often several times higher.

In order to integrate fine dust pollution into the regulation of a controlled indoor climate that is as healthy as possible, several AERASGARD air quality sensors also feature a fine dust sensor.

Networking

When do I need a Modbus-compatible transducer and when do I need an EtherCAT-compatible transducer?

Modbus RTU and EtherCAT both enable serial communication between networkable devices. Modbus has become particularly popular in intelligent building automation, as it is based exclusively on open standards. Used on the RS485 port, Modbus allows up to 32 participants and transmission speeds of up to 115200 baud. With 19200 baud, line lengths of up to 1000 meters can be achieved.

EtherCAT is a particularly fast fieldbus system, in which data packets transmitted via Ethernet (TCP/IP) are no longer received and evaluated or transmitted by each participant. Instead, the devices pick up the data intended for them, or in turn continuously insert data. This enables extremely short cycle times of ≤ 100 µs for real-time applications. It is theoretically possible to operate up to 65535 participants on EtherCAT at data rates of 100 Mbaud and more. With EtherCAT P, wiring and interconnection costs are also reduced, as data and power flow via a single common cable. This system has proved its worth particularly in industrial installations.

S+S offers a growing number of multifunctional sensor devices in Modbus and EtherCAT P versions for temperature, humidity, air quality and pressure.

What is the baud rate for bus-compatible transducers?

The baud rate (Bd) is the speed at which bits are transmitted per second in data traffic. To communicate, the baud rate of all bus participants must be set to the same value. Higher baud rates are often desired, but are more prone to interference.

For our Modbus-compatible devices, the baud rate can be set by DIP switch up to 38400 Bd. For S+S EtherCAT P-compatible detection devices, the bus parameters are set by the bus master.

What is parity for bus-compatible transducers?

Collapsible row contentIn data transmission, parity refers to the even or odd number of data bits 1 in a data byte, including the parity bit (EVEN = even number, ODD = odd number). Parity must be set in the same way for all bus participants. This makes it possible to detect isolated bit errors in transmitted telegrams.

On our Modbus-compatible devices, parity can be set via a DIP switch. For S+S EtherCAT P-compatible detection devices, bus parameters are set by the bus master.

Motion and presence detectors

How do motion and presence detectors work?

In the dark, animals or people who are not moving are generally undetectable, but they can be detected by visual infrared detectors, as they emit heat. The purpose of motion and presence detectors in buildings, however, is first and foremost to detect people who are on the move, for example, in order to regulate heating or lighting according to room occupancy. The same applies to the monitoring of protection and security zones, courtyards and parking lots.

Our KINASGARD motion sensors feature an ultra-sensitive infrared sensor that reliably detects the slightest movement, even from a distance of 10 meters.