Frquently Asked Questions

If you can't find the answer to your questions here, call us at +44 (0) 1256 320244 to speak with one of our knowledgeable customer service representatives. You may also fax us at +44 (0) 1256 473680, or send us an email at sales@gems-sensors.co.uk

Point Level Products

What is the difference between Wet Sink and Dry Sink?

Wet sink - The load is energised ("ON") as long as the sensor tip is immersed in fluid.

Dry sink - The load is energised as long as the sensor tip is dry (i.e. not immersed in fluid).

What is meant by "CMOS/TTL logic?"

TTL stands for Transistor-Transistor Logic and is considered a logic family. A logic family is a collection of different IC chips that have similar input, output and internal circuit characteristics, but that perform different logic functions. CMOS, which stands for Complementary Metal-Oxide Semiconductor, is another type of transistor logic family that has become more popular than TTL in recent years thanks to higher speed and lower power consumption (e.g. the 0.5 mA associated with the CLS-1200's 5 VDC output option is sufficient to drive only one TTL logic gate versus ten CMOS gates). The majority of today's large-scale ICs, such as microprocessors, use CMOS.

What is the difference between "sinking" and "sourcing?"

Sinking and sourcing are terms used to describe how an associated load (the device being turned on or off by the sensor) is powered in relation to the sensor. Sinking, the more widely used of the two, involves the switching of load current (power) supplied by a power source external to the sensor. In a sinking configuration, current passes through the load first, through the output switch of the sensor second and lastly to ground. A sensor with a sinking output switches the ground, or negative, leg of the circuit. In contrast, sourcing refers to a configuration in which the sensor is the source of the current required to power the load. In a sourcing situation, current supplied by the sensor passes through the load second and then to ground. A sensor with a sourcing output switches the positive leg of the circuit.

Can you connect more than one 12 volt Sinking Electro Optic Sensor to the Opto Pak Controller?

The Opto-Pak controller was designed for just one relay output. However, when using 12 VDC Electro Optics in parallel with one Opto-Pak controller Part# 149536 or 149535 with Nema4X Enclosure, the following is possible:

Maximum capability: 100Ma

Maximum optic sensors: 4

Please note if wired in parallel anyone of the 4 sensors could activate the relay.

Does Gems offer an optic sensor with a time delay?

For large volume OEM applications, a custom time delay is available on the programmable microprocessor version of the ELS-1150, which can be programmed for on, off or both delays from 2 seconds to 255 seconds. All delays have a ±1 second tolerance. Call Gems for more information.

Will different liquid media affect the time delay for optic sensors?

If the viscosity is similar, the time delay should be the same for different media.

Is there a minimum current flow requirement for a standard 20VA reed switch?

Yes, very low currents (< 5ma) can prevent “cleaning” of the contacts or not have enough energy to maintain low contact resistance. 5ma is likely a good minimum for our standard 20 VA switch. But you also want enough voltage. Approximately, 5V, 5ma is a good minimum.

For low current switching we recommend a 10 VA reed switch which can better handle lower loads. (1ma for example)

Is there a preferred mounting position for the ELS-1150 and ELS-1150XP Optical sensor?

These sensors must be mounted horizontally or up to 45 degrees from horizontal only. Reason, possible drips on tip can cause false indication. Also do not want to create air pockets.

What is the diode part number that is referenced for inductive loads per the wiring diagram for an Optic sensor?

Reference Diode part# 1N4004, (400V peak input voltage)

What is the mating cable connector for a standard custom made LS-700 model type with a 2 pin connection?

Web search Brad Harrison series 702000.
Example: Brad Harrison part# 702000D02F060 is for a single ended straight 6ft length.

What is the mating cable connector for a standard custom made LS-700 model type with a 4 pin connection?

A: Web search Brad Harrison series 704000. Example: Brad Harrison part# 704000D02F060 is for a single ended straight 6ft length

What is the mating cable connector for a standard custom made LS-700 model type with a 5 pin connection?

Web search Brad Harrison series 705000. Example: Brad Harrison part# 705000D02F060 is for a single ended straight 6ft length

What is the standard thread callout for the mating connector on the LS-700 model type with optional pin connection?

It is ½-20 UNF-2A Reference.