myLab Precision Thermometer
High accuracy, and seamless integration with 3rd party software makes myLab
Precision Thermometer indispensable instrument in your laboratory and automated test
environments (ATE) suitable for multi-channel applications.
Need a different function or a special function, then just select a another configuration.
Connections
myLab Thermometer interfaces standard PT1000 probes via 4 wires
by using the Sensor Jack connector:
- High Supply
- High Sense
- Low Sense
- Low Supply
Measurements are taken deferentially between the High and Low Sense input
terminals, while the Supply pins provide the supply voltage.
To minimize noise we suggest to use a shielded cable, terminated to the GND pin at
Jack side only, with two twisted-pairs for High/Low Sense and High/Low Supply signals.
Supply to the probe is provided only during a measurement process to
minimize the self-heating effect in high precision measurements.
Application Programming Interface
myLab Thermometer programming interface is inspired by a Standard Commands for
Programmable Instruments (SCPI).
Commands, states, and readings are sorted in a structure as described in the
following sub-sections.
Values represented in italic format can only be read, not settable.
Values in <…> are numerical values.
Measurements
- Measure.Temperature = <value> [V]
- Represents the latest temperature measurement.
When
Trigger.Source = Single then query this parameter to perform
a conversion.
- Measure.UTClock = <value> [ms]
- Time-stamp of the
Measurement.Temperature copied from the USB.UTClock
at the time A/D sample is available.
Sense Options
- Sense.Temperature.Aperture = <value> [s]
- Reflects the aperature time based on
Sense.Temperature.NPLCycles settings.
It cannot be entered.
- Sense.Temperature.NPLCycles = AC1 | NotSynced
- Determines the number of integration cycles. Currently supported is
one AC cycle or not synced to the AC line frequency
System.LFrequency.
Calculate Options
- Calculate.Average.Count = <0..255>
- Number of samples to average after A/D conversion (sensing).
- Calculate.Average.TControl = Repeat
- Clear average data and counter and restart the average process.
- Calculate.Average.Type = Scalar
- Averaging method currently supported.
Trigger Options
- Trigger.Source = Immediate | Single
- When Immediate system re-trigger immediately after conversion.
When Single a Query request to Measure.Temperature triggers next
conversion.
System Options
- System.Reset = Ok | Reset | Bootloader
- Determines the state or the last reset state.
When Ok system started successfully.
Setting to Reset will restart the system, and Bootloader option
will enter the system upgrade mode.
- System.Error = <errorCode>
- Error reporting codes.
- System.LFrequency = <50 | 60> [Hz]
- Select the line frequency in conjunction with
Sense.Temperature.NPLCycles.
- USB.UTClock = <value> [ms]
- A free running clock used to time-stamp measurements in the
Measurements.UTClock.
- myLab.RrefAccuracy = <0.10 | 0.01> %
- Displays myLab resistance reference accuracy.
Specifications
| Parameter |
min |
typ |
max |
Unit |
Notes |
|---|
| Temperature Measurement Range |
-80 |
|
+266 |
°C |
Can be extended by firmware |
| myLab Measurement Accuracy |
0.08 |
0.06 |
|
°C |
Valid for 0.01% Rref |
| myLab Measurement Accuracy |
|
0.5 |
|
°C |
Valid for 0.1% Rref |
| Long Term Stability |
<50 |
5 |
|
ppm |
Valid for 0.01% Rref |
| PT1000 Nominal Impedance |
|
1000.0 |
|
Ohm |
At 0 oC |
| Sample Rate (no AC rejection) |
|
|
|
sps |
|
| Sample Rate (50 HZ rejection) |
|
|
|
sps |
|
| Sample Rate (60 HZ rejection) |
|
|
|
sps |
|
| Noise, N=1 (no averaging) |
|
|
|
°C |
Peak-to-Peak |
| Noise, N=2 (averaging) |
|
|
|
°C |
Peak-to-Peak |
| Noise, N=4 (averaging) |
|
|
|
°C |
Peak-to-Peak |
| Noise, N=10 (averaging) |
|
|
|
°C |
Peak-to-Peak |
| PT1000 Supply Voltage |
|
|
|
V |
Use in PT1000 self-heating calculation |
PT1000 Temperature Probe
myLab interfaces standard PT1000 sensor with nominal resistance of 1000.0 Ohm at 0 °C.
To the above accuracy specifications, add the PT1000 Accuracy Class, to obtain total
measurement error:
- Class B: +/- 0.3°C in range -50..500 °C
- Class A: +/- 0.15°C in range -30..400 °C
- Class 1/3B: +/- 0.1°C in range 0..150 °C
- Class 1/5B: +/- 0.06°C in range 0..100 °C
- Class 1/10B: +/- 0.03°C in range 0..100 °C
and PT1000 Self-Heating Effect, which needs to be calculated per probe.
Consider also the maximum temperature range of the probe cable:
- Teflon, typ. max temperature 250 °C
- Silicon, typ. max temperature 200 °C
