Displacement Measurement System For Small Size Vessel Autosamplers & Test Tube Pipette Racks

Displacement Measurement PROBLEMS & SOLUTIONS:

PROBLEM: The customer has a circular rack of test tubes containing up to 20 test tubes which is rotated around the center by a servo motor. The tubes can be capped or uncapped, of varying diameters, and with varying fluid levels. The customer desires a measurement system to capture a two dimensional picture of his rack so that he can determine the capped/uncapped status of a particular test tube, the height and diameter of the test tube and the liquid level in the test tube. SOLUTION: Cosense’s single channel ML measurement system (ML-101 series) with a single Cosense Ľ” diameter ML sensor solved the customer’s problem. The circular rack was in constant motion at a known velocity (during all measurements) and the ML system was run in a continuous data acquisition mode. The resulting data was collected and analyzed by the customer’s controller unit. Using the fact that the rack itself always reports a certain distance, the customer was able to determine all of the desired information mentioned regarding the test tubes plus the recognition of an empty slot in the rack.

PRINCIPLES & OPERATION:

CONTROL UNIT INSTALLATION 1. Open the control unit enclosure and remove the printed circuit board. 2. Replace printed circuit board and route power and control wiring to the enclosure. Observe all applicable local electrical codes and wiring procedures. 3. Connect power and control wiring to the control unit as shown in Wiring Diagram (see figures 2 and 3). 4. Be sure that all wiring is carefully dressed to prevent pinching between the housing and the cover. SENSOR INSTALLATION The sensor is mounted on the top of the vessel with the sensor facing downward. A clear path, free of any obstructions must be provided between the sensor and the liquid surface. Due to the narrow sensor beam pattern, vertical axis positioning of the sensor is important. The sensor must be installed perpendicular to the liquid surface. 1. For a sensor provided with an NPT threaded fitting, drill a suitable hole in the vessel top and tap for the correct NPT thread. In thin walled vessels, or vessels constructed of material not suitable for tapping, weld or braze a bushing to accept the sensor. 2. Screw the sensor into the threaded fitting being careful not to cross thread the sensor. When possible, the use of a pipe compound or sealing tape is recommended. AVOID OVER TIGHTENING! 3. For flange mounted sensors, simply bolt the sensor / flange assembly to the proper mating flange connection. 4. Route the sensor cable to the electronic control unit and connect per the Wiring Diagram (see figures 2 and 3). IF ROUTING THE SENSOR CABLE THROUGH CONDUIT, A DEDICATED CONDUIT SHOUT BE UTILIZED. AVOID ROUTING THE SENSOR CABLE IN CLOSE PROXIMITY TO ANY SOURCE OF ALTERNATING CURRENT OR RFI. CAUTION: DO NOT ATTEMPT TO REMOVE A THREADED SENSOR FROM THE VESSEL WITH THE CABLE ATTACHED TO THE CONTROL UNIT, OTHERWISE IT MAY DAMAGE CABLE.

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For Further Information on Liquid level Contact Your Nearest Cosense Representative By Calling (631) 231-0735 or email us at sales@cosence.com

Untitled Document COSENSE PRODUCTS |

Liquid level detector Features with the ML Series

Operating Range: 0.5" - 6" (12mm-153mm)

Vessel / tube opening (diameter) as small as 1/8" (3.2mm)

Non-contact, ultrasonic operation eliminates contamination of sample media, while maintaining high system throughput

No calibration or special installation requirements

PC Compatible

Measurements are not affected by liquid color, density, opacity

Fast response time - Programmable

Standard Accuracy ±0.1mm (±.005")

ML-101/102/104

Greater Accuracy ±0.1mm (±.005")

Higher Accuracy ±0.005mm (±.0002")