Bathroom scales

Electronic bathroom scales

A bathroom scale is a commodity used to determine body weight . The measurement result can be read on an analog or digital display.

The measuring range is different depending on the design. The lower limit is usually 4 to 6 kg (below this, 0 kg is displayed regardless of the actual load). The upper limit is usually at least 130 kg, with obesity - scales kg and up to the 300th

Measurement methods

Bathroom scales are available in different designs. The models are basically differentiated according to their measurement method :

Mechanical measurement

The mechanical bathroom scale is a spring scale . The weight force proportional to the mass is determined by the deformation of the spring and the result is transferred to the analogue scale display by means of gear wheels . The markings are always arranged in a ring, but the design varies: only one segment of the display is visible on the rotary scale . The pointer is fixed, the scale rotates. With the full view scale ( full screen scale ) the entire display is visible. Here a pointer mounted in the middle rotates over a stationary scale.

The scale division is usually 1,000 g, less often it is 500 g increments.

Electronic measurement

The electronic bathroom scale is a spring scale with a very stiff spring. The deflection is measured electrically with a strain gauge , electronically processed by a microchip and made readable as a digital number display on an LC display or LED display . If installed under a tinted glass plate, the display field is not visible when switched off. It is switched on via a foot sensor and switched off automatically. For models with WLAN or Bluetooth synchronization , the measurement data is automatically fed into an app.

Due to their finer scale (reduced to 50 g), electronic bathroom scales pretend to measure more precisely than mechanical ones. However, tests have shown that only calibrated scales meet this requirement.

Mass comparison measurement

Running weight scales have a bar with a sliding counterweight. Unlike mechanical and electronic scales, these beam scales do not weigh by weight measurement, but by mass comparison . The constant counterweight can be moved on a lever arm provided with a scale. If the two masses are the same, the position of the barrel weight shows the weighed mass - a very common principle with historical bathroom scales.

Mechanical balance with rotary scale
Full view scale on a baby scale
Bathroom scales with WiFi synchronization
Barrel weight scale, Berlin, 1971

Types of construction according to application

Floor scales or bathroom scales : During the weighing process, the person stands with both feet on the platform of the scales. The weight display is usually arranged in the middle in the area of the toes. The floor scale is the most common type of bathroom scale and can be found in almost every household.

Seat scales or chair scales : The design, which is visually comparable to a wheelchair , is suitable for weighing physically weak or mobility- impaired patients and is mostly used in hospitals or retirement homes . If there are ramps on both sides , it is a wheelchair scale .

Baby scales or baby scales: With hanging scales and bowl scales, a distinction is made between two designs. With hanging scales , the baby is hung on the scales in weighing trousers or a weighing cloth. Because these scales are compact and lightweight, they are mostly used by midwives on their home visits. With bowl scales , the baby is placed in a cradle. A pan scale is stable and heavy and is therefore mostly used stationary. There are collapsible models for mobile use.

Obesity scales: Personal scales for overweight people have a higher weighing range, a more stable weighing plate and a larger step surface for a safe stand. The weighing range is generally 300 kg, with a division of 100–200 g.

Public bathroom scales : installed in a public area , some of these historical scales still work today. After inserting a coin , they show the person willing to weigh the body weight. Some models print the result on a weighing card and eject it.

Body fat scales : A design of the digital personal scales. By measuring the complex resistance of the body from one leg to the other, the amount of fat in the body is determined.

Body analysis scales : Further development of the body fat scales. In addition to the fat content, the body's water content and muscle mass are also determined.