Using The External Probe - OHAUS Guardian 3000 Handbuch

EN-14
HEATING OPERATING TIPS
Overshoot:
The unit may overshoot the temperature up to 10° C before stabilizing at the
setpoint. The two methods to minimize overshoot are:
1. Metal containers minimize overshoot.
CAUTION! When heating metal containers on a ceramic top plate, it is
recommended to use the lowest temperature setting possible to limit
thermal stress to the ceramic top plate.
2. If a glass vessel is used, anticipate overshoot. Start with a temperature
setpoint 5 to 10° C below the desired temperature. When the temperature
stabilizes at this lower setting, increase the heater to the final temperature.
Overshoot is then reduced to about 1° C.
The temperature display on the unit represents the estimated top plate temperature,
not the sample temperature.
When external probe is in use, the temperature display on the unit represents the
sample temperature. The vessel contents being heated may be at a lower
temperature depending on the size and thermal conductivity of the vessel.
It may be beneficial to monitor the temperature of the vessel contents and adjust
the setpoint temperature accordingly. If you need precise control, use the Ohaus
External Temperature Probe.
Typical Time to Boil Water
The chart below is an example of an approximate time to boil for the specified
amount of water in a specific vessel. These values are only approximate and can
vary from unit to unit. Values are based on 23° C water in an ambient environment
of 23° C.
Unit Size Heater Temp. Limit
Round Top
7×7
4×4
3.5.

Using the External Probe

1. Connect the Ohaus External Temperature Probe to the External RTD
Probe Port on the rear panel of the unit.
Once the Ohaus External Temperature Probe is connected, the External
Probe Icon
Volume of Water
500mL in 1L beaker
400° C
500mL in 1L beaker
500° C
500mL in 1L beaker
500° C
External RTD Probe Port
on the screen will illuminate.
TM
Guardian Hotplate-Stirrers
Typical Time to Boil
≈ 25 min
≈ 18 min
≈ 30 min