- Chemically resistant ceramic sensor with FKM sealing
- Vacuum connection by small flange, G1/4 female thread or screw in hose nozzle
- High repeatability
- Very good long term stability
- Battery life time up to 5000 h
€ 387,00 excl. VAT and transport costs
The versatile VD81 digital vacuum meter with data logger and USB interface measures absolute pressure in the rough vacuum range.
|Dimensions||12 x 6 x 4.7 cm|
Piezo resistive, independent of gas type
|Materials In Contact With Vacuum||
Stainless steel 1.4305, Al2O3 ceramic, FKM
1600 – 1 mbar (1200 – 1 Torr), max. overpressure 4 bar absolute
1 mbar (Torr)
< +-0.3% full scale (linearity, hysteresis, repeatability)
1.0 s (100 ms in data logger mode)
|Data Logging Rate||
9 V block battery or 12… 15 VDC external
Mini-jack 2.5 mm for plug-in power supply
Approx. 2 mW (clocked)
9 V lithium battery: max. 5000 h, 9 V Alkaline 6LR61 battery: max. 2500 h, NiCd rechargeable battery 150 mA: max. 500 h
Sensor integrated in the instrument
DN 16 ISO KF with G1/4 female thread or hose nozzle (accessory VD81SW1)
LCD 12 mm
What is meant by “piezoresistive”?
By changing the pressure, a thin membrane deforms on which a resistor bridge is mounted on the rear. These piezoresisitive resistors change with strain and pressure. The resulting deformation is used to measure the absolute pressure.
What is the Min/Max memory functionality?
Extreme values (minimum and maximum pressure) recorded during the measurement process are stored directly in the instrument and can be shown on the display when the measurement is complete.
Is it possible to place a VD8 compact vacuum meter directly into the vacuum for measuring?
Yes, our VD8 compact vacuum meters can be directly placed into a vacuum chamber. With their data logger functionality the measurements are stored and can be sent to a PC for evaluation, when the measurement is complete.
What happens with the instruments’ parameters or stored data when the battery is changed?
A memory chip, which works independent from a battery, is used for storage of measurements and the instruments’ parameters. However, the extreme values (Min/Max memory) will be lost when the battery is changed. Poor battery power is indicated by the “BAT”-prompt in the upper left corner of the display. The device can still be used.
Is the battery included in the shipment?
The instrument can be operated on batteries, rechargeable batteries, or with an external power supply. These items are available as optional accessories.
What battery types are suitable for VD8 compact vacuum meters?
We recommend 9 V alkaline batteries. Alternatively 9 V lithium batteries or 9 V rechargeable batteries can be used. Zinc coal batteries are not suitable for the VD8, due to its high internal resistance.
How often do I need to recalibrate the compact vacuum meter?
This depends on the specific application. Especially if there are coatings and contaminations on the sensor-head or if it is used in extreme temperature conditions it can be necessary to readjust the instrument. For quality assurance matters, we recommend to return the instrument for calibration every one or two years. We can offer a works calibration (item no. ADJCERT) or a DAkkS calibration (item no. DKDCERT).
Do I have to mount the instrument into a specific position?
Basically the instruments can be mounted in every position. The best accuracy is achieved if the flange of the instrument is mounted horizontally, because the instruments are calibrated in this position. Also it is not recommended to mount the sensor at the bottom of a pipe, because condensate and dirt could be collected in the sensor cell.
What possibilities for data storage are available with VD8?
With the integrated data logger up to 2000 measurements can be stored in the instrument and sent to a PC when the measurement is complete. Alternatively the data can be sent and evaluated with the PC during the measuring process (online measurement).
What use is the functionality “Data logging at measurement change” ?
To optimally use the memory, especially for long term measurements, the VD8 offers the functionality “Data logging at measurement change”. Measurements are only logged if the pressure changes, thus reducing the amount of insignificant data.
Is the VacuGraph® software required for using a VD8 compact vacuum meter?
No. The VacuGraph® software is only required for the communication between a PC and vacuum meter. So you can e.g. transfer the measurements stored in the data logger to a PC for evaluation or you can change parameters, like the sample rate, comfortable in the configuration board of the software.