CPT6010 Operating Instructions
27
Digital Pressure Transducer
CPT6010
Substitute the required password in place of “PW” in the following examples:
1. Find the current zero offset and make a note of the returned value.
Send: #*ZC?<cr><lf> and record the reading.
2. Use the setup for absolute pressure shown in Figure 7.2. Apply a stable pressure value between
600 mTorr absolute and 20% of the transducer’s span.Measure the reference presure reading in
the native units of the CPT6010. This reading becomes the “true pressure”.
3. Clear the current zero offset from RAM.
Send: #*PW<cr><lf>
Next send: #*ZC 0<cr><lf>
4. Determine the current pressure reading.
Send: #*?<cr> and make a note of this reading.
5. Subtract the current pressure reading from the true pressure (vacuum) reading.
The difference is the zero offset now required.
Example: For a 0-15 psia unit with 600 mTorr absolute pressure applied, using psi units:
600 millitorr = 0.0116 psia (true pressure)
Current pressure reading (from step 4) = –0.0011 psia
True pressure – current pressure = new offset
0.0116 – (–0.0011) = +0.0105 psi offset
6. Enter the new offset into memory.
Send: #*PW<cr><lf>
Then send: #*ZC<sp>.0105<cr><lf>
The new offset of 0.0105 will now be added to all pressure readings.
Send: #*SAVE<cr><lf> to store the new value in non-volatile memory.
7. To check the zero correction:
Send: #*?<cr><lf>
For 600 mTorr the pressure reading returned should be 0.0116 psia.
