Thermometer, Hygrometer
No permanent data record
Shows no historical data – only current values
Cannot provide a permanent record for documentation purposes.
Drum recorder
Drum recorder has significantly greater physical dimensions typically 5 to 10 times the volume of the Humigraf +.
Drum recorder is significantly heavier – typically four to eight times the weight of the Humigraf +
The paper must be changed frequently – typically weekly or monthly
The recording mechanism is subject to wear, ink has to be refilled and the pens have to be changed regularly
The drum mechanism means that the pressure record of pressure variation is often printed on a curved, rather than a linear axis – which makes quick and accurate interpretation of the data difficult.
No digital display
No additional functions such as Alarm, display of Minimum and Maximum values, memory.
Data logger
Laptop required
Display only visible if the laptop is running
Stored data unsuitable for use for legal / documentation purposes, as this can easily by manipulated by PC
