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VD003

Voltage Divider TwinSite® Sender

Application

Rochester TwinSite® Senders are utilized where direct reading plus accurate variable voltage output signal to a remote receiver is required. Models are available to fit all Rochester Junior and Senior gauges equipped with a large Alnico magnet. Some applications require use only with intrinsically safe circuits.

General Information & Features

This three-wire Voltage Divider TwinSite® Sender incorporates a 10,000 or 15,000 ohm advanced matrix film-conductive polymer element in conjuntion with a multi-fingered contact arrangement. This unique combination in the level-gauge industry provides better inherent accuracy and reliability than conventional one- or two-wire resistance senders. Accuracy is not reduced due to changes in temperature, the multiple contact fingers provide for increased reliability, and the thick-film polymer resistance element insures greater durability. Electical connections are sealed with multiple epoxy chambers. The connecting wires are also sealed behind this epoxy barrier. This sealing process helps prevent sparks or other damage due to inadvertent short circuits, as well as, providing an impervious barrier to the environment.

The sender is mounted onto the Rochester Junior® or Senior gauge with #0040-00416 stainless steel dial screws (6 – 32 x 3/8”). An additional item available to ensure weatherproof connections from the TwinSite® to the receiver is heat shrink solder sleeves part number 0025-00495.

Resistance Senders and Voltage-Divider Senders Compared

A resistance-sender output is the variable resistance measured between one end of the resistance element and the wiper pickup contact. Because of this, resistance senders are quite sensitive to changes in contact resistance and other factors. The receivers used with resistance senders are calibrated to indicate at a specific graduation when specific resistance input is received. When the resistance varies for any reason, the Voltage-Divider TwinSite® Sender reading on the receiver will vary, also. Since standard resistance senders are supplied in narrow ranges of 0-90, 70-10 and 240-30 ohms, it is apparent that small changes in the element or contact resistance will yield sizable errors in receiver readings.

On the other hand, a voltage-divider sender output is a variable percentage of the voltage drop across the entire resistance element. The output voltage is measured between the low end of the resistance element and the wiper pickup contact. When the voltage drop across the element varies due to changes in input voltage or other factors, the output voltage remains the same relative percentage of the total voltage. The voltage divider utilizes a 10,000 or 15,000 ohm resistance element, and it is necessary that the wiper pickup contact be connected to a high impedance load. Because of these factors, any likely change in element or contact resistance will result in a negligible change in output voltage and receiver reading.

Documents

Data Sheet

General Specifications*

Nominal Resistance

10K ohms ±5% or 15K ohms ±5%.

Dynamic Noise

Less than 1% of total resistance.

Rotation Life (E to F To E Cycles)

500,000 minimum.

Resolution

Infinite.

Power

0.5 watts maximum, impedance of load to wiper = 100K ohms minimum.

Repeatability

±2%.

Conformity

±3% maximum output deviation. (Float gauge errors not included).

Moisture

Unit is ultrasonically sealed.

Vibration

Suitable for mobile service applications.

Operating Temperatures

-40° F to 158°F, -40°C to 70°C.

 

When Ordering Specify:

1. Gauge model number.

2. Tank diameter and riser height.

3. Mounting location.

4. Any listed options.

5. Mobile Model.

Materials of Construction*

Crystal & Case

Polycarbonate or polyamide.

Pointer

Acetal.

Magnet

Neodymium.

Contact and Contact Spring

Proprietary multi-fingered construction.

Resistance Element

Proprietary advanced matrix film.

Dial

Painted aluminum.

 

*Materials and specifications are subject to change without notice. Pressure ratings subject to change due to temperature and other environmental considerations.

 

WARNING! This sensor is not to be used as the primary means of determining high or low fuel condition. It must not be used in the absence of redundant systems in critical applications where there may be significant safety risk or financial exposure in the event of fuel overfill or fuel exhaustion condition. This sensor is not to be used for tank filling.

 

03-10-2015