HF scientific Micro200BW Turbidimeter - 0 -1000 NTU - Manual (Page 45)

Page 31
MICRO 200 BW 0 - 1000 NTU (5/05)
Rev. 3.1
"Sensor Fail"
VII. TROUBLESHOOTING
A. GENERAL NOTES
Service and technical support are available from the manufacturer, HF scientific inc. from 8:00 AM to 4:00 PM Eastern
Standard Time.
The following Table will supply fundamental troubleshooting information. The Guide assumes that the controls and
functions of the instrument are used correctly. The intention of the guide is to eliminate common faults, not to
troubleshoot down to component level.
GUIDE TO FUNDAMENTAL TROUBLESHOOTING
SYMPTOM SOLUTION
Display not lit. 1. Make sure that the unit is plugged in and turned on. Make certain that your power
source is providing the correct voltage.
2. Check analyzer fuse. Refer to page 8 for correct fuse size and instructions for
changing.
3. Shut off power for about five seconds and then turn it back on. This will initiate
a power on reset.
4. If none of the above steps correct the problem, contact HF scientific, inc. service
dept. for additional support.
Instrument not functioning 1. If sensor cable was removed from the analyzer, check wiring connections.
correctly.
Cannot leave. menu.
1. Invalid parameters may have been inadvertently set. Examples of this are a bad
time or date or the lower limit set higher than the upper limit. Check the screen
and change any invalid numbers.
Display response slow. 1. Select a lower averaging time.
Sensor alarm on. 1. Replace the lamp module.
2. Check the connection at the sensor.
3. The turbidity may be too high.
4. Replace the sensor. If you have a spare sensor or another MICRO 200 BW you
may use the alternate sensor to determine if the sensor in question is defective.
Readings lower than 1. Recalibrate with known good standards.
expected.
Readings higher than
1. Check the flow through cuvette. If it has dirt on either the inside or outside
expected. or is scratched, clean the cuvette or replace it.
2. Check for condensation on the outside of the cuvette. If condensation is present
either the desiccant tray needs replacement or the vaporpurge system of the
sensor is defective. Replace the desiccant or the sensor.
3. Recalibrate the sensor with known good standards.
Readings erratic. To check if the erratic readings are due to sample measurement or a problem with the
instrument, remove the flow through unit and place a light shield over the sample
well. This may be left for a period of time and the graphic history observed later. If
the graph shows instability the MICRO 200 BW has a problem. Call HF scientific
service dept. If the graph is stable there is a problem with the sample being measured.
See the following for suggested corrections.
1. Check for debris in flow through cuvette. Clean out as required.
2. Increase back pressure with flow control valve. This will keep air in solution.
Analyzer Displays 1. Reset by turning analyzer power off and then on again. "0-1000 range 1000 NTU
calibrate" should only be performed with a 1000 NTUstandard in sensor well.