Grant Instruments SBB Aqua Plus - Manual (Page 9)

SUB, JB & SBB Aqua Plus 29825 Ver. 2 - July 2010 71W
Operating Manual Page 8
www.grant.co.uk
EN
5.2.4 Setting the sample protection thermostat
The bath is fitted with an adjustable sample protection thermostat to protect the sample.
This device is not a safety feature. The sample protection thermostat can be set to be a
few degrees above the bath set temperature.
1. Wait for the bath to stabilise at the correct temperature (can be checked with external
thermometer if needed).
2. Turn the sample protection thermostat control knob slowly anti-clockwise until an
audible „click‟ is heard (and the heater lamp goes off if it was on) and then turn it
clockwise until another audible „click‟ is heard.
In the unlikely event of failure of the primary temperature control system, the sample
protection thermostat will maintain the water in the bath at a temperature a few degrees
above the control temperature. This will be indicated by the two orange lamps cycling on
and off. If this happens, first check that the sample protection thermostat is not set to a
lower temperature than the primary control system. If that is not the reason, the main
control thermostat is not operating correctly. The bath can continue to be used without
compromising the safety of persons or the surroundings until current work is completed.
However, it is recommended to have the bath checked by a competent person as soon
as conveniently possible.
5.2.5 Calibration of the temperature control knob
If the control temperature does not match the actual water temperature measured with a
thermometer then a calibration of the control knob is required.
1. Carefully remove the temperature control knob marker to expose the adjustment
screw.
2. Use the 1.5mm Allen key supplied with the bath to loosen the adjustment screw so
that the knob can rotate on the shaft.
3. Set the knob at the bath temperature as measured by the thermometer then tighten
the adjustment screw.
4. Carefully replace the temperature control knob marker.