Calibration commands - HMT130

HMT130 User Guide

Document code
M211280EN
Revision
D
Language
English (United States)
Product
HMT130
Document type
User guide
Serial commands that are related to calibration are described in this section. For the actual calibration procedures, see Calibration and Adjustment on page 58.
Table 1. CRH command
Syntax Description
crh<cr>

Use the crh command to perform a 1-point or 2-point humidity (RH) calibration.

When performing a 1-point calibration, you need to place the probe in a single humidity reference with RH < 50%. Run the command and enter the exact RH of the reference after the measurement has stabilized. Exit the command by pressing the ESC key before proceeding to the second point (see example 3).

To update the value, press ENTER without inputting a value. For 2-point calibration, the first point requires a RH < 35% humidity reference, the second point must be RH > 50%.

Example 1: 1-point calibration
>crh
RH:         11.29915720 Ref1 ? 11.3
Press ENTER to continue or ESC to exit
OK
> 
Example 2: 2-point calibration
>crh
RH:         11.29915720 Ref1 ? 11.3
Press ENTER to continue or ESC to exit
RH:         75.04306440 Ref2 ? 75
OK
> 
Example 3: No calibration, only updating the value
>crh
RH:     20.28000200 Ref1 ?
RH:     20.14000000 Ref1 ?
Calibration terminated with ESC
> 
Table 2. CRHCLR command
Syntax Description
crhclr<cr>

Use the crhclr command to restore the probe RH factory calibration.

Example:
>crhclr
OK
> 
Table 3. CT command
Syntax Description
ct<cr>

Use the ct command to perform a 1-point or 2-point temperature calibration.

When performing a 1-point calibration, you need to place the probe in a single temperature reference. Run the command and enter the exact temperature of the reference after the measurement has stabilized. Exit the command by pressing the ESC key before proceeding to the second point. To update the value, press ENTER without inputting a value.

For 2-point calibration, the second reference point must be at least 30 °C (86 °F) warmer than the first. The measurement reading for the second point will appear when this requirement is met.

Example 1: 1-point calibration
>ct
T  21.9827 Ref1 ? 22
Press ENTER to continue or ESC to exit
OK
> 
Example 2: 2-point calibration
>ct
T  22.0007 Ref1 ? 22
Press ENTER to continue or ESC to exit
T  54.9847 Ref2 ? 55
OK
> 
Example 3: No calibration, only updating the value
>ct
T  22.0007 Ref1 ?
T  22.0145 Ref1 ?
Calibration terminated with ESC
> 
Table 4. CTCLR command
Syntax Description
ctclr<cr>

Use the ctclr command to restore the probe temperature factory calibration.

Example:
>ctclr
OK
> 
Table 5. ACAL command
Syntax Description
acal<cr>

Use the acal command to calibrate the analog current loop outputs.

After you give this command, the CH1 analog output of the transmitter is set to the low limit (4 mA). Measure the output and enter the measured value. After entering the low limit, you must measure and enter the high limit (20 mA) also. The same procedure is then repeated with CH2. Calculated coefficients are printed after the measured values are given.

Example:
>acal
Ch1  I1 (mA)  ? 5.60
Ch1  I2 (mA)  ? 18.40
 -1.40562890E+03 a0  
  1.41171900E+03 a1
OK
Ch2  I1 (mA)  ? 5.60
Ch2  I2 (mA)  ? 18.40
 -1.40562890E+03 a0
  1.41171900E+03 a1
OK
> 
The question mark is displayed after a certain stabilization time has expired. Only enter values after the question mark is displayed. Values entered before the question mark are discarded.