SPECIFOCATIONS:
Model: XHST820
DO Range: 0~20mg/L(ppm)
Resolution: 0.1mg
DO Accuracy: ±0.5mg/L
% Saturation of Oxygen: 0~200.0%
Accuracy: ±10.00%
Temperature Range: 0.0~100.0ºC
Temperature Accuracy: ±0.1ºC
Temperature Compensation: 0~40ºC
Salinity Correction: 0~35g/L
Barometric Pressure Correction: 450~850mmHg
Calibration Points: 2 points
Memory: 48 Data Sets
Output: USB
Power: 1*9V Battery
Battery Life: 100 hours
Dimensions: 185(L)*mm88(W)mm*32(H)mm
Weight: 300g

Model: XHST821
DO Range: 0~20mg/L(ppm)
Resolution: 0.1mg
DO Accuracy: ±0.3mg/L
% Saturation of Oxygen: 0~200.0%
Accuracy: ±3.00%
Temperature Range: 0.0~100.0ºC
Temperature Accuracy: ±0.1ºC
Temperature Compensation: 0~40ºC
Salinity Correction: 0~35g/L
Barometric Pressure Correction: 450~850mmHg
Calibration Points: 2 points
Memory: 48 Data Sets
Output: USB
Power: 1*9V Battery
Battery Life: 100 hours
Dimensions: 185(L)mm*88(W)mm*32(H)mm
Weight: 300g

Features:
* Microprocessor based
* Single or Two points automatic calibration
* Hold function
* Automatic temperature compensation
* Auto-Power Control
* Adjistable barometric pressure and salinity correction
* Automatic messages
* Expanded memory stores and recall up to 48 Data Sets
* USB interface and application software
* Large LCD display