CONTENTS ... 1 SECTION 1: HAZARDS... 2 SECTION 2: DESCRIPTION AND USE ... 5 SECTION 3: TECHNICAL SPECIFICATIONS ... 6 3.1
REGULATORY DETAILS... 7
SECTION 4: INSTALLATION AND SET-UP... 9 4.1 4.2 4.3 4.4 4.5
UNPACKING AND PACKING ... 9 INSTALLATION ... 9 BOX CONTENTS ... 9 LOCATION ... 10 OPERATOR’S TIPS ... 10
SECTION 5: PRINCIPLES OF OPERATION ... 11 5.1 5.2 5.3 5.4 5.5 5.6 5.7
INSTRUMENT DESCRIPTION ... 11 CONNECTORS... 12 PRECONDITIONS... 12 CALIBRATING THE UNIT ... 13 PERFORMING A MEASUREMENT ... 13 ELECTROMAGNETIC INTERFERENCE INFORMATION ... 15 TROUBLE SHOOTING... 15
SECTION 6: CLEANING AND MAINTENANCE ... 20 6.1 6.2 6.3
CLEANING THE OXOID TURBIDOMETER ... 20 MAINTENANCE ... 20 DECONTAMINATION ... 20
SECTION 7: WARRANTY ... 21 7.1 7.2
WARRANTY DURATION ... 21 PARTICULAR EXCLUSION ... 21
Operating Cautions and Limitations to Use IMPORTANT The Oxoid Turbidometer is designed and constructed to be safe during use provided that the operating precautions outlined in this document are fully observed.
Operating Cautions IT IS ESSENTIAL THAT THE USER OF THIS MANUAL IS AWARE OF THE POTENTIAL HAZARDS ASSOCIATED WITH THE INSTRUMENT. ALL OPERATORS MUST BE FAMILIAR WITH THE SAFETY PRECAUTIONS AND WARNINGS GIVEN IN THIS SECTION BEFORE ATTEMPTING TO OPERATE THE INSTRUMENT. The following symbols are used on the Instrument and in this Manual.
CAUTION/WARNING Risk of electric shock.
CAUTION Refer to Operator’s Manual
The precautions to be observed relate to the transportation and use of all types of solid state electrical/electronic instrumentation. The precautions are outlined below:
AC Power Supply 1)
The Oxoid Turbidometer’s PSU must be plugged into a suitable AC outlet. WARNING: Always plug the Instrument into a properly Earthed, three pronged socket. Do not use nonEarthing adapters.
To unplug the PSU from the supply always disconnect from the AC outlet. Firmly grasp the plug and pull. WARNING: Do not remove the plug by pulling the line cord.
Environment WARNING: Do not use the Instrument in any area which has, or is thought to have been exposed to explosive gases.
Instrument button Do not use excessive force when pressing the calibrate button on the instrument front panel.
Instrument environment and static electricity Do not expose the Instrument to extremes of temperature (see Specification). As with all solid state equipment, minimise exposure to electro-static charges.
Instrument Handling The Instrument is portable. However, it must not be dropped or subjected to rough physical handling.
Instrument Covers No maintenance which requires the removal of the Instrument’s covers should be undertaken by the Operator. Maintenance which requires the removal of the covers should be undertaken only by trained personnel.
Description and Use
The Oxoid Turbidometer is designed to compare the concentration of prepared inoculum to a 0.5 McFarland standard. The instrument is able to qualitatively assess whether the concentration of inoculum is over, under or equal to 0.5 McFarland. Measurement of the concentration of inoculum can be carried out in a clear glass tube with an external diameter of 12mm using a variety of growth media in solution: Growth Medium Brain Heart Infusion Broth Buffered Peptone Water Peptone Water Todd-Hewitt Broth Tryptone Soya Broth Ringers Solution Physiological Saline
Oxoid code CM 225 CM 509 CM 009 CM 189 CM 129 BR 52
The Oxoid Turbidometer is designed for use in laboratories.
Oxoid Turbidometer: Dimensions: Width x depth x height (mm)
Weight Input Voltage
5V DC +/- 5%
Operating Relative Humidity
10% to 80%, non-condensing
Ambient Temperature Range
18°C to 28°C (operating) +20°C to +40°C (storage)
External PSU: Dimensions: Width x depth x height (mm)
57x75x93 500 g
Weight Line Voltage (US) (EC)
100 – 120 VAC 220 – 240 VAC
5V DC +/- 5%
18°C to 28°C (operating) +20°C to +40°C (storage)
Jack socket 2.5mm
The Oxoid Turbidometer conforms to the following general, safety and EMC requirements:
EC directives 89/336/EEC and 72/23/EEC
IEC 1010 - 1990 - Amendment No 1 BSEN61010-1: 1993
EN50081-1 : 1992 EN50082-1 : 1997 EN61326-1 : 1997 EN61000-3-2 : 1995 FCC Class A - Sub. Part J
Compliance of the Oxoid Turbidometer with Part 15 of the FCC Rules states the operation of the instrument is subject to the following conditions: 1. The device may not cause harmful interference 2. The device must accept any interference received, including interference that may cause undesired operation. The Oxoid Turbidometer is manufactured within the scope of the BS EN ISO 9001 Quality Management System.
DECLARATION OF CONFORMITY The Oxoid Turbidometer has been designed in accordance with, and satisfies, the requirements of article 11 of the Low Voltage Directive 72/23/EEC as realigned by 93/68/EEC on the harmonisation of the laws of the Member States relating to electrical equipment designed for use within certain voltage limits, to the essential requirements of BS EN 61010-1: 1993. The Oxoid Turbidometer has been type tested by EMC Projects, a NAMAS approved test house, and issued a certificate of compliance project number P1849 to the following EMC Standards: EN 50081 : 1992 EN 50082 - 1 : 1997 IEC 801-3 : 1984 IEC 801-4 : 1988 IEC 801-2 : 1984 Covering: Conducted Emissions, Radiated Emissions, Electrostatic Discharge, Radiated Immunity, & Fast Transient Bursts. Satisfying the EMC Directive(s) 89/336/EEC and 92/31/EEC as realigned by 93/68/EEC Signed ……... Richard Huggins Quality Manager Oxoid Limited United Kingdom
Section 4: 4.1
Installation and Set-up
Unpacking and Packing
Before opening the boxes: Make sure that no damage has been caused during transportation. If damage has occurred, make a claim to the transport company and notify Oxoid Limited. When opening the boxes: Make sure that all the items described in this manual are present. Keep packaging material in case the instrument is to be moved.
Ensure that you have read all the Operator’s Manual before installing the instrument. Before connecting the AC power supply adapter, check that the power supply corresponds to the adapter’s characteristics. An appropriate mains socket is necessary for use. Before use, allow the instrument to stand for at least half an hour to stabilise with room temperature. Note: If the equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired.
1 Oxoid Turbidometer 1 External PSU 1 Silica gel pack 1 Operator’s Manual
The Oxoid Turbidometer is designed to be used on a laboratory benchtop but may be moved depending on the needs of the user. Place the instrument on a flat, horizontal, and vibration-free surface. The area should be free from dust. The room temperature and relative humidity should be constant and within defined operating parameters. Do not place the instrument near strong sources of electromagnetic interference. Avoid using the Oxoid Turbidometer under strong sources of light. Do not use the instrument near sources of heat.
Never insert anything sharp into the test well area, this will cause damage to sensitive optical surfaces at the bottom of the well. Never insert fingers into the test well area. Do not expose the Turbidometer or its power adapter to moisture or use them near sources of water such as taps. If there is a large fluid spillage in the test well area, do not attempt cleaning by tools.
Section 5: 5.1
Principles of Operation
Unit Front Panel Under normal operation, the CALIBRATE button and indicators have the following purposes: POWER – this green indicator is illuminated when the unit is supplied with power via the connector at the rear of the unit. TEST WELL – this opening accepts 12mm (OD) tubes for reading and calibration. The tube is positioned and retained by a tensioning spring. <0.5 – this amber indicator is illuminated if the result is 20% less than 0.5 McFarland. =0.5 – this green indicator is illuminated if the result is equal to 0.5 +/- 20% McFarland. >0.5 – this amber indicator is illuminated if the result is 20% greater than 0.5 McFarland
CALIBRATE – this button is used to request that the unit is calibrated; the red indicator flashes when the unit requires calibration – see “5.4 Calibrating the Unit” on page 13.
Connectors POWER IN – this socket is located on the rear of the unit. Use only the AC power adapter provided with the unit. Before inserting, ensure that the DC jack plug of the external adapter is clean and free from grease or other marks that can degrade its electrical contact with the Turbidometer.
NOTE: After connecting the power adapter, the unit enters a short period of approximately 10 seconds of warm-up phase during which time the CALIBRATE indicator is continuously lit. Attempting to use the instrument during the warm-up period will result in an error indicated by lights flashing After this period the CALIBRATE indicator will start flashing and the unit can be calibrated, ready for use.
For reliable and accurate measurements, the following preconditions should be applied to both the calibration standard and normal sample tubes: • •
The surface of the tube must be clean and free from fingerprints, scratches and other marks. There should be a minimum of 25mm of liquid in the bottom of the tube.
NOTE: It is recommended that only glass tubes be used in this unit. The optical reliability of plastic tubes can not be guaranteed.
Calibrating the Unit
Each time the unit is switched on, or whenever the red CALIBRATE indicator is flashing, the unit must be calibrated using a known 0.5 McFarland standard: 1.
Press and hold the CALIBRATE button – the indicator will start flashing quickly; now release the CALIBRATE button. The instrument is now in calibration mode. VORTEX the 0.5 McFarland calibrator tube for 5 seconds, invert slowly to remove bubbles and insert fully into the test well. Whilst the green =0.5 indicator is flashing, slowly twist the test tube.
If calibration is successful, the green =0.5 indicator will stay on, and the red CALIBRATE light will turn off, otherwise both of the amber <0.5 and >0.5 indicators will flash and the above procedure should be repeated. NOTE: It is recommended that the calibration procedure is performed regularly e.g. before performing measurements on a large sample batch. In particular, it is important to re-calibrate the unit for different media or when there have been changes in ambient light and temperature conditions.
Performing a measurement
Before performing a measurement, ensure that the instrument is calibrated using the same tube type and growth medium as the sample to be measured. If the CALIBRATE indicator is flashing, re-calibrate the unit using the procedure described above. The Oxoid Turbidometer can be recalibrated to a different tube type or growth medium at any point by performing the calibration as above.
To perform a measurement of a sample, simply: VORTEX the sample tube for 5 seconds, invert slowly to remove bubbles. Insert the test tube fully into the test well. Whilst the green =0.5 indicator is flashing, slowly twist the test tube. The result will be displayed: <0.5, =0.5 or >0.5. However, if both of the amber indicators are flashing, the reading was unsuccessful and should be repeated, using a different test tube.
Electromagnetic Interference Information The Turbidometer is designed to meet all relevant EMC directives. However, if electrical interference is experienced when using the Turbidometer, the following actions are recommended to the operator: 1. 2. 3.
Move or re-orientate the Turbidometer away from the interference source. Connect the equipment causing the interference to an electrical power outlet on a different circuit to that which is used for the Turbidometer. If possible, switch off the equipment causing the interference.
Trouble Shooting Key:
Meaning: Problem can be fixed by the operator. Problem can not be fixed by the Operator, return the unit for repair. See “Section 7: Warranty” on page 21.
Cause / Action required
Green POWER indicator does not come on
AC power adapter not plugged in unit AC power adapter not plugged and switched on at wall socket Faulty power adapter or cable Fuse blown
Unit uncalibrated <0.5, >0.5 and Calibrate indicators flashing
Test well excessively dirty – clean test well, see “6.1 Cleaning the Oxoid Turbidometer” on page 20. Tube retaining spring is jammed – exercise spring to work it loose
Both amber indictors (<0.5 and >0.5) flash when calibrating unit
Dirty or finger-printed test tube – clean tube surface and try again Nearby equipment producing electrical noise. Move Turbidometer away from interference source. Incorrect tube size used – ensure 12mm OD glass tube in use. Tube rotated in well too fast- clean tube surface and try again Air bubbles on inside surface of tube – invert tube two or three times to dislodge air bubbles. Tube scratched or flawed – use new tube and try again Tube inserted too slowly into test well, or not fully inserted Calibration standard settled – vortex tube, invert to remove bubbles and try again Calibration standard expired – make new standard in a new tube Test well excessively dirty – clean test well, see “6.1 Cleaning the Oxoid Turbidometer” on page 20.
Both amber indictors (<0.5 and >0.5) flash when measuring a normal sample
Dirty or finger-printed test tube – clean tube surface and try again Nearby equipment producing electrical noise. Move Turbidometer away from interference source. Incorrect tube size used – ensure 12mm OD glass tube in use. Tube rotated in well too fast- clean tube surface and try again Tube removed prior to completion of reading. Try again ensuring tube not removed until = indicator stops flashing and result displayed. Air bubbles on inside surface of tube – invert tube two or three times to dislodge air bubbles Tube scratched or flawed – use new tube and try again. Tube inserted too slowly into test well, or not fully inserted. Unit not properly calibrated – recalibrate unit, with a new calibration standard in a new tube. Test well excessively dirty – clean test well, see “6.1 Cleaning the Oxoid Turbidometer” on page 20.
CALIBRATE button does not respond when pressed
Tube in TEST WELL – remove it Tube retaining spring is jammed – exercise spring to work it loose CALIBRATE button fault
CALIBRATE indicator starts flashing even though unit was previously calibrated
The unit must be calibrated each time it is powered up, and then re-calibrated every 24 hours thereafter. Instrument temperature has changed significantly since it was last calibrated – recalibrate the unit. Instrument not fully stabilised with room temperature
<0.5, = and >0.5 indicators flashing rapidly
Tube left in test well before powering up – remove it. Instrument temperature is outside 18-30oC temperature range, move instrument to another area. Leave instrument to stabilise to room temperature. bad or dirty power supply connector, clean jack plug connector and re-insert. Unit fault . Instrument to be returned. CALIBRATE button jammed. Faulty spring Two different types of tube used. Use same tubes for all samples Dirty or finger-printed test tubes – clean tube surfaces and try again Tube surfaces scratched or flawed – use new tubes and try again. Sample is borderline. Change sample dilution. Different media used to make 0.5McFarland calibrator. Repeat calibration for media in use. Different tube type used to measure 0.5McFarland calibrator. Repeat calibration using equivalent tubes as used for samples. Calibration tube dirty, scratched or flawed- recalibrate using new clean tube. Calibrator out of date- re-calibrate with fresh 0.5McFarland standard
Two repeat measurements of the same sample give different results.
High turbidity sample gives <0.5 result.
Low turbidity sample gives >0.5 result.
Different media used to make 0.5McFarland calibrator. Repeat calibration for media in use. Different tube type used to measure 0.5McFarland calibrator. Repeat calibration using equivalent tubes as used for samples. Tube surfaces scratched or flawed – use new tube and try again Dirty or finger-printed test tubes – clean tube surfaces and try again Calibrator out of date- recalibrate with fresh 0.5McFarland standard.
Cleaning and Maintenance
The Turbidometer must be switched off before any cleaning and maintenance
Cleaning the Oxoid Turbidometer
The Oxoid Turbidometer must be cleaned: • If a tube has been broken inside the reading block • If the results are erratic • Regularly to keep it clean and free from dust and dirt which may impair the readings. The Oxoid Turbidometer should be cleaned with a cotton swab using 0.25% Presept, 70% Isopropanol or Virkon. WARNING: Before using any cleaning or decontamination method other than recommended by the manufacturer, users should check with the manufacturer that the proposed method will not damage the instrument. Do not place fingers in the tube well.
Maintenance CAUTION: DO NOT use solvents or strong cleaning solutions as these may deform the Instrument’s plastic components.
Any instrument returned to manufacturer must be supplied with a decontamination certificate.
The supplier warrants the Oxoid Turbidometer, when purchased new, to be free from defects in materials and workmanship and will repair or replace at their discretion any instrument which, used under proper conditions, exhibits such defects. Under the terms of this warranty, the product must be returned fully decontaminated, appropriately packaged (preferably in original packaging), transportation prepaid with a copy of proof of purchase to your Oxoid representative.
This warranty is provided to the original purchaser for 12 months from the date of manufacture.
Unauthorised modification of any part of the Oxoid Turbidometer will void this warranty.