A limit switch allows operators to automate an industrial process without the need of the person-in-charge on-site. Operators can predetermine a threshold value and configure them to generate a warning or an alarm when the flow rate measured by the variable flow meter reaches a certain value in the measurement scale, whether it is a maximum or minimum flow.
- Bistable contact, Normally Closed
- Bistable contact, Normally Open
- Changeover contact
The MSK limit switches consist of a limit switch (reed switch) that is switched over by the magnet integrated in the float. The limit switch is guided in a guide slot in the protective case and can be adjusted over the full measuring range. The reed switches have a bistable characteristic.
Uncontrolled current and voltage peaks can occur in the case of inductive or capacitive loads, e.g. from contactors or solenoid valves. Such peaks will also occur, depending on cable geometry, where cables exceed a certain length.
Recommendation: Use a contact protection relay that will increase the contact rating and prevent occurrence of inductive and capacitive peaks, thus ensuring long service life of the contacts.
The MSK limit switches can be equipped with:
- Direct reading on calibrated tube
- Range: From 0.1 l/h up to 1,500 m³/h
- Accuracy ±2 %
- For liquid or for gas
- Materials: Glass, steel or stainless steel
- Optional:
Adjustable contacts
Analogue output 4-20 mA or 0-10 Volt - ATEX version on request
- For liquids and gases
- Direct reading on a calibrated tube
- Ranges from 0.5 l/h up to 160 m³/h
- Materials: Glass, steel or stainless steel
- Optional:
Adjustable limit value switches
Analogue output: 4-20 mA or 0-10 V - ATEX version on request
- Direct reading on a calibrated tube
- Body: PVC / Reading tube: Glass
- For aggressive fluids and corrosive environment
- Fittings: Unions or flanges
- Optional: Adjustable limit value switches
- Direct reading on a calibrated tube
- Water: Up to 16 m³/h ; Air: Up to 160 m³/h
- Body: Stainless steel
- Optional:
Adjustable limit value switches
Analogue output: 4-20 mA or 0-10 V - ATEX version on request
- Changeover contact, Normally Open without flow
- Changeover contact, Normally Closed without flow
They are slipped on to the guide on the flow meter and can be set to any desired value on the appropriate scale.
A magnet built into the float closes or opens a potted reed contact in the limit value switch. The switching function is bistable, which means that the switching status is maintained even when the magnetic float is located a distance away from the contact.
Recommendation: It is recommended to use a contact protection to prevent overloads and inductive or capacitive loads that may damage the contacts.
- Direct reading
- All wet parts in plastics
- Measuring tubes: PVC or Polysulfone
- ranges: Up to 60 m³/h
- Specific scales for Air, HCl, NaOH, etc.
- Optional:
Adjustable contacts
4-20 mA transmitter
- Direct reading
- All wet parts in plastics
- Materials: PVC, PSU, PVDF, EPDM
- Scales from 2.5 up to 1,000 l/h of water
- Other scales: Air in Nm³/h, HCl and NaOH.
- Optional: Adjustable contacts
The Z42 / Z40 limit switches can be equipped with:
